Tektronix 2715 User Manual
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Tektronix 2715 User Manual

Spectrum analyzer
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User Manual
2715
Spectrum Analyzer
070-9115-05
This document supports
firmware version 2.14.97 and above.

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  • Page 1 User Manual 2715 Spectrum Analyzer 070-9115-05 This document supports firmware version 2.14.97 and above.
  • Page 2 Copyright E Tektronix, Inc. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved. Printed in the U.S.A.
  • Page 3 Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located.
  • Page 5 1–2 About the 2715 ...........

  • Page 6: Table Of Contents

    5–1 General (CATV) 2715 Mode ........
  • Page 7 ............F–3 Glossary and Index 2715 User Manual...
  • Page 8 ....3–8 Figure 3–9: The 2715 Back Panel ......
  • Page 9 ......6–35 Figure 6–9: 2715 Plot with Title and Plot Labels ....
  • Page 10 ..E–9 Figure E–6: 9-Pin Female to 25-Pin Female Null-Modem Cable ..E–10 Figure E–7: 9-Pin Female to 25-Pin Male Extension Cable ..E–11 2715 User Manual...
  • Page 11 ......F–1 Table F–3: Power Cord Identification ......F–2 2715 User Manual...
  • Page 12 Table of Contents viii 2715 User Manual...
  • Page 13 Do Not Operate With Suspected Failures. If you suspect there is damage to this product, have it inspected by qualified service personnel. Do Not Operate in Wet/Damp Conditions. Do Not Operate in an Explosive Atmosphere. 2715 User Manual...
  • Page 14 WARNING indicates an injury hazard not immediately accessible as you read the marking. CAUTION indicates a hazard to property including the product. Symbols on the Product. The following symbols may appear on the product: WARNING Protective Ground CAUTION Double High Voltage (Earth) Terminal Refer to Manual Insulated 2715 User Manual...
  • Page 15 Institute of Electrical and Electronic Engineers Inc. Change/History Information Changes to the 2715 may occur or manual errors may be found that make some of the information in the manual inaccurate. When this happens, Manual Change Information notices containing the corrected information are inserted at the rear of the manual.
  • Page 16 Specific Introduction contains a brief description of spectrum analysis and reviews the characteristics of the Tektronix 2715 Cable TV Spectrum Analyzer. Getting Started enables you to safely apply power and signals to the spectrum analyzer. You become acquainted with the fundamental controls of the instru- ment and make your first measurements using a firmware-based CATV measurement routine and the built-in calibration signal.
  • Page 17 Appendix B: Broadcast AM, FM & TV Signal Sources describes connecting the 2715 to various signal sources to do the examples shown in the manual. Appendix C: System Messages describes abnormal instrument operating situations and the recommended resolution or correction.
  • Page 18 Preface 2715 User Manual...
  • Page 19 Introduction...
  • Page 21 Introduction This section introduces you to the basic concepts of an RF spectrum analyzer and its uses. This section also briefly describes the features of the 2715 Cable TV Spectrum Analyzer. What is a Spectrum Analyzer? There are several types of spectrum analyzers, but we will describe only the heterodyne, or scanning, spectrum analyzer.
  • Page 22 About the 2715 The Tektronix 2715 Cable TV Spectrum Analyzer is a portable, cable TV, radio frequency (RF), scanning spectrum analyzer for use in the field or in the shop. It weighs less than 22 lbs (9.5 kg) and can be equipped with a battery and inverter for use in locations without AC power.
  • Page 23 TV program in progress. Since gated-measurement techniques have advantages and disadvantages, the 2715 Spectrum Analyzer is designed so that you always have a choice of whether or not you use gated (in-service) measurement techniques. If you follow the In-Service menu selections for C/N, CSO, or ICR, you will be making a gated measurement;...
  • Page 24 Introduction 1–4 2715 User Manual...
  • Page 25 Getting Started...
  • Page 27 Packaging and Storing In the event that the equipment must be returned to a Tektronix Service Center, carefully package it in the original shipping container. Use the vinyl vapor barrier, and insert the original foam blocks in the same fashion they were received.
  • Page 28 Getting Started The 2715 can be stored up to 90 days in an environment that meets the nonoper- ating specifications. It is suggested that you provide a dust cover. For longer periods, the 2715 should be enclosed in a vapor barrier containing appropriate desiccant material and stored in an environment that meets the nonoperating specifications.
  • Page 29 RF attenuation when connecting a signal with a DC component. Then remove attenuation as needed to make the measurement. Also, be aware that the 2715 is optimized for a –30 dBm input to the first mixer. A larger input signal may lead to nonlinear operation and inaccurate results.
  • Page 30 2. Press the POWER switch. The green LED adjacent to the power switch lights indicating that power is turned on. The LED indicators flash and you hear a few beeps as the 2715 performs its power-up self test. When power is applied to the 2715, it initializes its front-panel controls to settings stored in memory.
  • Page 31 Additional information about normalization may be found in Normalizing the 2715 on page 6–65. 1. To do an initial normalization of the 2715, ensure that no external signals are connected to the 2715. 2. Press [UTIL] and [3].

  • Page 32: Figure 2-1: Display With Factory Default Power-Up Settings

    Press [UTIL] [1] [1]. This restores the factory-default settings whenever the 2715 is in normal spectral display mode (and most other modes). It is a handy method of returning to a fixed set of conditions if you get lost.

  • Page 33: Figure 2-2: Normal On-Screen Data Readouts

    In this mode, the first item in the left column lists the frequency at the location of the frequency marker (the intensified spot on the display). 2–7 2715 User Manual...
  • Page 34 The arrow keys enable you to instantly change control settings. [ b ] and [ y ] move according to the channel table selection. The arrow keys are active whenever the spectrum analyzer is in the spectral display mode. 2–8 2715 User Manual...
  • Page 35 If the error alert is turned on and an abnormal condition exists, such as a request to extend a measurement parameter beyond its range, the 2715 emits a high-level beep. A message is simultaneously displayed on-screen describing the abnormal condition.
  • Page 36 The 2715 is equipped with a built-in calibration source. The calibrator for the 2715 has no external “Cal Signal” output. Instead, the calibrator resides in the 2715 and can be “connected” to the input path without the need for external cabling by selecting the proper Input Menu option.
  • Page 37 6. Press [W] after the channel number has been entered. This key can represent units of CHAN, GHz, SEC, or V. Because you selected an entry mode that requires a channel, the 2715 correctly interprets the currently displayed entry as STD CH 8.
  • Page 38 H Run the measurement The channel table and measurement channel selected at power down will be remembered when power is reapplied to the 2715. Therefore, the only thing that needs to be selected after that is the type of measurement.

  • Page 39: Figure 2-3: Typical Measurement Result Display

    This is the safe setting for introducing new signals. It enables you to view the entire measurement range (1.8 GHz) of the spectrum analyzer. If a smaller span is used, large signals can be present off-screen. 2–13 2715 User Manual...

  • Page 40: Figure 2-4: The Primary Controls

    First, raise the displayed signal height by reducing the reference level. The reference level represents the signal power needed to deflect the displayed spectrum to the top graticule line. The 2715 provides several methods of directly changing the reference level. The most convenient method is to press the arrow keys.

  • Page 41: Figure 2-5: Calibrator Signal And Harmonics

    30 dB. For numeric entry, the W key terminates any channel number; whereas, the X, Y, or Z keys terminate channel/frequency entry. On channel/frequency, the 2715 selects the channel closest to the new channel/frequency. Figure 2–5 shows what the resulting display should look like, although some of the signal peaks on your spectrum analyzer may have slightly different ampli- tudes than those shown.
  • Page 42 20.8 dBmV. If the currently selected reference level units had been dBm or dBW, the 2715 would have interpreted your entry correctly when you pressed the terminator key.
  • Page 43 2715 correctly interprets the currently displayed entry as 6 MHz. If a time or voltage unit had been required, the 2715 would have interpreted your entry as 6 ms or 6 mV, respectively.
  • Page 44 (0.02 times the span/div, or 0.12 MHz in this case). The control functions as the “fine” frequency adjustment. Rotating the knob clockwise increases the frequency at the same rate. 17. Continue turning the knob in either direction until the signal is centered. Your screen should now resemble Figure 2–6. 2–18 2715 User Manual...

  • Page 45: Figure 2-6: Calibrator Signal Fundamental

    20.8 dBmV ref level – 0.2 div 10 dB/div = 18.8 dBmV Using only the frequency, span, and reference level controls you have verified the basic operation of the 2715, and determined the frequency and amplitude of its calibrator signal. 2–19...
  • Page 46 Getting Started 2–20 2715 User Manual...
  • Page 47 Operating Basics...

  • Page 49: Figure 3-1: Layout Of The Text Screen In The Spectral Display Mode

    Keypad entry/WFM to Save Real-time Clock Display ”CALIBRATOR” Indicator ”WARMUP TIME 15 MIN” Message/GPIB & RS-232 Status May also contain C/N, NOISE NORM’D, BW, & OBW results. Figure 3–1: Layout of the Text Screen in the Spectral Display Mode 3–1 2715 User Manual...

  • Page 50: Figure 3-2: Layout Of The Text Screen In The Menu Display Mode

    (or start) frequency, span, and reference level controls. For convenience, one function block is dedicated exclusively to menu display. The control panel and its major functional areas are shown in Figures 3–3 through 3–8. The Dedicated Controls section contains detailed discussions of the controls. 3–2 2715 User Manual...

  • Page 51: Figure 3-3: The Frequency/Marker Function Block

    Two quick presses enter the signal track mode (continuously repeated center measures, enabling a drifting signal to be tracked); signal frequency readout is optional in this mode and is enabled by pressing [MKR/FREQ] [9] [1]. A third press returns to normal operation. 3–3 2715 User Manual...

  • Page 52: Figure 3-4: Fundamental Analyzer Controls

    Selects the span per division for the immediate entry mode. SPAN appears on the screen at left center. Enter the desired span/div from the keypad; terminate with [Hz], [kHz], [MHz], or [GHz] key. Range: 1 kHz to 180 MHz 3–4 2715 User Manual...
  • Page 53 REF LVL STEP Toggles the amount by which the REF LEVEL arrow keys change the reference level between 1 dB and 10 dB per press. The adjacent FINE indicator is illuminated when 1 dB is selected. 3–5 2715 User Manual...

  • Page 54: Figure 3-5: The Keypad

    (saved or current), the red LED to the lower right of the key is lighted. When SAVE ENABLE is armed, press [A], [B], or [C] to store the current sweep if the register is cleared, or clear the register if it contains saved data. 3–6 2715 User Manual...

  • Page 55: Figure 3-7: Vertical Scale And Other Controls

    Scale factor is controlled by the reference level controls in the LIN mode and by [10/5/1] in the LOG mode. PLOT Initiates a screen plot on an optional printer or plotter. Plotter and interface must be correctly configured (see System Configuration on page 6–67). 3–7 2715 User Manual...

  • Page 56: Figure 3-8: Resolution Bw And Sweep Control

    However, pressing [VID FLTR] (see Figure 3–8) toggles an alternate, automatically selected or user-designated video filter on and off. Its bandwidth replaces the normal video filter readout. Figure 3–8: Resolution BW and Sweep Control 3–8 2715 User Manual...
  • Page 57 3 Hz to 300 kHz and WIDE in a 1–3 sequence SINGLE Press [SINGLE] to place the 2715 in a single sweep mode similar to a conven- tional oscilloscope. SGLSWP MODE appears on the screen. With the 2715’s sweep in free run mode (default), press the key again to start a sweep. In other trigger modes, the sweep begins with the first trigger signal following entry into single sweep.

  • Page 58: Figure 3-9: The 2715 Back Panel

    Option 15 First LO Output SMA Female 50W (For Model 1405 TV TRIG Sideband Analyzer or v50V 2707 External Tracking Generator) Communications Connector (Depends on Interface Selected – See Programmer Manual) Figure 3–9: The 2715 Back Panel 3–10 2715 User Manual...
  • Page 59 H INPUT Some of the submenus are used for servicing; information about these submenus is in the optional 2715 Spectrum Analyzer Service Manual. Refer to Table F–2: Optional Accessories on page F–1 for the part number of the service manual.
  • Page 60 6 SPECTRAL DISPLAY IN MENUS 7 SWEEP HOLDOFF 0 SET DAY 1 SET MONTH 2 SET YEAR 3 SET HOUR 4 SET MINUTE 5 SET SECONDS TO :00 6 DISPLAY DATE/TIME Displayed when selected plotter language is HPGL. 3–12 2715 User Manual...
  • Page 61 0 CENTER/START FREQ 1 COUNTER RESOLUTION COUNTER OFF WHEN TRKG (1 HZ) 1 1HZ 3 FREQ OFFSET 2 1KHZ 4 FREQ OFFSET MODE Displayed only if KNOB SELECTABLE is se- lected in the SWEEP MENU SETUP TABLE. 3–13 2715 User Manual...
  • Page 62 2 DISPLAY RESULTS 3 PRINT CURRENT RESULTS* 4 PRINT STORED RESULTS* 5 SET UP AURAL (FM) DEVIATION TEST MODES 6 ENTER ADJUSTMENT MODE 0 INTERACTIVE 1 AUTO 9 LEAVE AURAL (FM) DEVIATION 5 MEASUREMENT TIME RS-232 only. 3–14 2715 User Manual...
  • Page 63 0 NO REF WITH REF REFERENCE ACQUISITION 2 START FREQUENCY 3 STOP FREQUENCY 4 USE DEFAULT START/STOP 5 ACQUIRE NEW REFERENCE 6 STORED REFERENCE MENU 7 EDIT CURRENT REFERENCE NAME** **Displayed only if a reference has been acquired. 3–15 2715 User Manual...
  • Page 64 7 EDIT CHANNEL TABLES 6 User Defined CATV Measurements Page 2 7 User Defined 8 REMOVE ALL STORED RESULTS 8 User Defined 9 LEAVE CATV MEASUREMENTS SETUP 9 User Defined Option 50 and Option 75 only 3–16 2715 User Manual...
  • Page 65 2 User Defined 3 User Defined (-750.000KHZ Default) 4 User Defined (-1.25000MHZ Default) 5 USE DEFAULT TEST FREQUENCIES CONTINUOUS MODE PARAMETERS*** 6 CARRIER FREQ*** 7 TEST INTERVAL*** 8 NORMALIZATION INTERVAL*** Displayed only if CONTINUOUS mode is selected. 3–17 2715 User Manual...
  • Page 66 TEST FREQUENCIES 2 User Defined (-500.000KHZ Default) 3 User Defined (+500.000KHZ Default) 4 User Defined (+1.25000MHZ Default) 5 User Defined (+2.00000MHZ Default) 6 User Defined (+3.00000MHZ Default) 7 User Defined (+3.75000MHZ Default) 8 USE DEFAULT TEST FREQUENCIES 3–18 2715 User Manual...
  • Page 67 2 NOISE NORM’D BW 3 PERCENT OCCUPIED BW DEMOD Menu Structure 0 OFF 1 AM DEMODULATOR 2 FM DEMODULATOR 3 BROADCAST (AM) VIDEO 9 VIDEO MONITOR SETUP 0 VIDEO DETECT MODE 1 SYNC POLARITY 2 VIDEO POLARITY 3–19 2715 User Manual...
  • Page 68 4 PAUSE FOR “USER DEF” KEY 5 CONTINUOUS EXECUTION 6 STORE 7 DELETE 8 PROTECT 9 TIME DELAY SETUP 0 SET DAY 1 SET HOUR 2 SET MINUTE 3 REPEAT INTERVAL 4 RUN N TIMES 5 CLEAR TIME 3–20 2715 User Manual...
  • Page 69 6 MEASUREMENT DIST 6 ANTENNA SETUP 1 START FREQUENCY 7 SAVE RESULTS IN WFM 2 STOP FREQUENCY 3 INC FREQUENCY 4 REFERENCE DISTANCE 9 MARKER DISPLAY 0 ON/OFF 1 ATTEN/AMPL ENTRY *Not available in CATV Measurements Mode. 3–21 2715 User Manual...
  • Page 70 Operating Basics 3–22 2715 User Manual...

  • Page 71: Dedicated Controls

    Dedicated Controls...

  • Page 73: Fundamental Operations

    Dedicated Controls This section describes in detail the dedicated controls of the 2715. All of the dedicated controls are on the 2715 front panel except the trace alignment controls, which are on the back. These dedicated controls are used to carry out the most common and general spectrum analyzer operations without the need to call up the menus.

  • Page 74: Span/Div

    H Resolution BW changes automatically as the span changes (later, we show how this can be changed) If you request a narrow span before the 2715 is completely warmed up, you may get a NORMALIZATION SUGGESTED message. This message should not appear after the 2715 warms up.
  • Page 75 400 MHz. . There is often a need to view the entire input frequency range of the 2715, such as when connecting new signals to the 2715 input. In this mode, the 2715 is in MAX SPAN.
  • Page 76 12. Press [MAX] a second time to return to 20KHZ/. Many of the keys on the 2715 are toggle action. The ability to undo an action by pushing the same button that carried out the action is typical. MAX is a toggle-action key taking you from the current span/div to 180 MHz/div and back.

  • Page 77: Frequency Entry

    2715 is in the spectral display mode. Keypad Entry. CHAN/FREQ defaults to CHAN whenever the CATV mode is active. The abbreviation CHAN appears at left center of the 2715 screen. CHAN indicates that you can enter the channel number directly from the keypad. This is done by keying in a permissible channel number (according to the selected channel table) followed by [W].
  • Page 78 The up arrow selects the next channel, and the down arrow selects the previous channel. This means that even though the 2715 is in the CATV mode, you can increase and lower the center frequency by the channel allocation width using the up and down arrows.

  • Page 79: Frequency Entry (Noncatv Mode)

    . On the other hand, had you wanted the entry to represent a frequency of 1.25 GHz, you would have pressed [1] [2] [5] [0] [X]. (Use the correct multiple and [X] to select GHz while the 2715 is in the CATV mode.) Now use the direct entry method to set the center frequency to 100 MHz: 13.
  • Page 80 2715 low-frequency specification is 9 kHz. Your entry can contain up to 25 characters, but regardless of how many you enter, the 2715 attempts to control frequency to the nearest hertz, and the frequency is displayed at the top of the left-hand data column to 1% of the span/div.

  • Page 81: Ref Level

    2715 is in the spectral display mode. NOTE. The direction of the arrows always represents the direction of change of the 2715 setting. ([ y ] adjacent to [REF LEVEL] increases the reference level and lowers the displayed signal height.) 4–9...
  • Page 82 2715 correctly interprets the currently displayed value as 21.3 dBmV when you press [Y]. If a frequency unit had been required, the 2715 would have interpreted your entry as 21.3 kHz when you pressed [Y]. On the other hand, had you wanted to enter a negative reference level, you would have pressed [Z] for –dBx.

  • Page 83: Enhanced Versatility

    5MHz RBW (AUTO) Channel Table Name CH nn CALIBRATOR The Res BW controls select the 2715 resolution bandwidths of 300 Hz to 5 MHz and allow time to be automatically selected to match the selected bandwidth. 4–11 2715 User Manual...
  • Page 84 300 Hz, 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz, 300 kHz, 1 MHz, and 5 MHz in the 2715. It is important to know how far signals must be separated before we can see them as separate.
  • Page 85 To understand what has happened, you must recall the process going on within the 2715. It is sweeping a narrow-band signal (the calibration signal) past a broadband filter (the 5 MHz resolution filter). As the signal is moved past the filter, it maps the shape of the resolution filter.

  • Page 86: Video Filter

    Dedicated Controls 11. Press [AUTO] to place the resolution bandwidth in the automatic mode. The red LED lights. You can take the 2715 out of AUTO mode by pressing a RES BW arrow key or by pressing [AUTO]. 12. Set the span/div to 50 MHz.
  • Page 87 The following steps demonstrate the effects of the video filter: 1. Ensure that the 2715 is set as in the settings box on page 4–14, and note if the signal peaks at 700 MHz, 800 MHz, and 900 MHz are visible.

  • Page 88: Vert Scale

    10/5/1. This label expresses the three logarithmic vertical scale factors available on the 2715: 10, 5 and 1 decibels per major vertical division. Press the key to cycle the vertical scale factor through the three values in a 10 dB –5 dB –1 dB –10 dB...

  • Page 89: Sweep

    10 DB/ 10KHz RBW (AUTO) The Sweep function block controls the 2715 normal sweep rate, auto sweep, and single sweep feature (other trigger modes are discussed in SWP/TRIG on page 6–83). The rate at which the CRT beam sweeps across the screen is known as the sweep rate.
  • Page 90 When AUTO sweep rate selection is active, the sweep rate selected by the 2715 depends on the span/div, resolution bandwidth, and video filter in use. Second, pressing the SWEEP AUTO key when the 2715 is in the single sweep mode exits from that mode.
  • Page 91 SWEEP function block exits from the single sweep mode. When a sweep begins will depend on how the 2715 is triggered. The factory default mode is free run; this is the mode the 2715 currently should be in. 15. Set the resolution BW to 3 kHz.

  • Page 92: Level

    When the sweep is completed, the SGLSWP MODE message reappears indicating the 2715 has completed the sweep and is ready to be rearmed. If the 2715 is not in the free-run trigger mode (see SWP/TRIG on page 6–83 to change modes), behavior is much the same.
  • Page 93 A saved sweep cannot be erased, modified, or updated without operator interaction. When the D green LED is lighted, the 2715 is in the “waterfall” mode. [A], [B], [C], and [D] are toggle-action keys that activate and deactivate the display registers. A register’s contents are displayed only when it is active (red LED lighted), although it still contains saved data as long as its green LED is lighted.
  • Page 94 The current sweep is saved and the B green LED lights. The register remains active, but because it is now saved, it is no longer updated. NOTE. Status of the red LED is not changed by the save operation. 4–22 2715 User Manual...
  • Page 95 A register. The register remains active, but the displayed spectrum is now updated during each sweep. The on-screen readouts are stored along with the sweep. Since the 2715 displays only one group of readouts at a time, the readouts for the highest priority register are displayed when multiple registers are active.
  • Page 96 All eight of the register status LEDs light and four traces appear. Registers A, B, and C must be cleared before the 2715 allows you to enter the waterfall mode, because the waterfall mode uses all four registers. This is a safeguard to prevent accidental overwriting of previously saved data.

  • Page 97: Figure 4-1: Example Of A Waterfall Display

    You can view any, all, or none of the registers. Turn them all off and the analog display reappears. However, the 2715 is still in waterfall mode. You cannot selectively erase a register or store new data in it without first exiting from the waterfall mode.

  • Page 98: Freq/Mkrs

    OFF key is a three-way toggle that enables you to control one, or a pair, of markers. A marker is a bright spot that appears on the digitized waveform. Markers can be used only with the digital display. When the 4–26 2715 User Manual...
  • Page 99 The corresponding signal amplitude and frequency are displayed on screen. The marker amplitude readout represents the most accurate method for determining signal amplitude with the 2715 (unless a separate, extremely precise signal is used for direct comparison). In general, amplitude accuracy is further enhanced if the signal being measured is first moved to within one division of the top graticule line using the REF LEVEL controls.
  • Page 100 If you attempt to move the movable marker past the edge of the display, you will see that the spectral display behaves almost the same as it did for the single 4–28 2715 User Manual...
  • Page 101 (changing the threshold is discussed in MKR/FREQ on page 6–17). When the marker is turned off, the signal peak nearest center screen is used. The 2715 then measures the signal frequency and makes it the new center frequency.
  • Page 102 (counter). The counter readout provides the most accurate frequency determination available on the 2715, and its resolution can be set to 1 Hz if desired. The counter readings disappear when a control setting is altered. The marker and counter amplitude readouts are equally accurate. However, the signal amplitude indicated by the position of the marker relative to the graticule may differ slightly from the readout.
  • Page 103 2715 detector. Because the output varies only if the signal is modulated, the counter is actually measuring the frequency of the modulation (if none is present, you receive a message saying so).
  • Page 104 41. Enter the delta-marker mode and press the arrow keys. The movable marker jumps in the direction of the arrows just as the single marker did, and the readouts behave as if you had manually moved the marker. 4–32 2715 User Manual...

  • Page 105: Miscellaneous Controls

    (see System Configuration on page 6–67). To make a plot of the screen, check that your printer or plotter is powered up, on line, and that the paper is in correct registry. Then, with the 2715 displaying the desired trace(s), press [PLOT].

  • Page 106: Figure 4-2: Typical Plotter Output Showing Tv Channel Spectrum

    Their appearance changes with sweep speed. By eliminating the readouts, you eliminate the dark areas. You will also notice that the trace has intensified. This is because the 2715 does not have to take time out from each sweep to write the on-screen data.
  • Page 107 If you have to turn it to full intensity, try reducing the ambient light or shielding the display. If the 2715 is used in direct sunlight, a contrast- enhancing light filter is recommended (part of the Travel Line Package, Option 33).
  • Page 108 Dedicated Controls 4–36 2715 User Manual...

  • Page 109: Catv Measurements

    CATV Measurements...

  • Page 111: Catv Preliminary Information

    CATV Preliminary Information This section provides information on input power limitations for CATV operation, an overview of CATV preparatory information, and specific 2715 CATV applications. CATV measurements and capabilities include the following:...

  • Page 112: Table 5-1: Safe Maximum Signal Levels

    Input Power Limitations CAUTION. To prevent damage, the safe maximum total RF input power for the 2715 is +70 dBmV. DC input voltage is limited to 100 VDC maximum. Total input power above the rated maximum can cause damage to the instrument and voids the factory warranty.
  • Page 113 AC or DC power supply voltages on the input of the 2715. Initial Setup At power-up, the 2715 comes up in the CATV mode tuned to the default power-up channel. The power-up channel is the last active channel when power was turned off or channel T–7 (labeled 907 in STD Table 5–4) if NVRAM was...

  • Page 114: General (Catv) 2715 Mode

    General (CATV) 2715 Mode If the 2715 is in the CATV mode, press [CATV/APPL] and the CATV mode comes up on the screen. If the 2715 is not already in the CATV mode, press [CATV/APPL] [8] [0] from the spectral display.

  • Page 115: Table 5-2: Signal Type Measurements

    Pilot Digital Carrier Level Avg Power Carrier Survey Modulation Depth Aural (FM) Deviation Carrier To Noise Desired/Undesired Hum/LFD Frequency Response View Field Modulation View Line Modulation View Picture Listen Cross Modulation Adjacent Channel Leakage 5–5 2715 User Manual...
  • Page 116 The 2715 Spectrum Analyzer with either Option 50 or Option 75 installed is capable of frequencies up to 2.15 GHz. For frequencies above 1.8 GHz you are limited to the 2715 front panel to create and edit the channel tables.

  • Page 117: Figure 5-2: Channel 2 Of The Std Channel Table Selected For Edit With Menu Set To Change Scrambled (Toggles Between Yes/No)

    (STD, HRC, and IRC), and the other source is the unlimited user defined tables. Up to seven of these user defined tables can be stored in NVRAM in the 2715. Press [CATV/APPL] [8] [1] to call up the channel table menu then press a number corresponding to the desired channel table to select the table.

  • Page 118: Table 5-3: Menu Selections

    If the channel TYPE selected is CATV or PILOT, the next line reads VISUAL FREQ. If the channel TYPE selected is DIGITAL or FM, the next line reads CENTER FREQ. The right MKR arrow toggles the SYNC polarity and the left MKR arrow toggles the VIDEO polarity. 5–8 2715 User Manual...

  • Page 119: Figure 5-3: Channel With Finish Selected

    The <ABORT ALL> selection copies the original table from NVRAM back to RAM, the channel table reverts to its original state, and the parent menu is displayed. A confirmation prompt is displayed before this complete loss of all edits can occur. 5–9 2715 User Manual...

  • Page 120: Table 5-4: Std

    151.25 155.75 157.25 161.75 163.25 167.76 169.25 173.75 175.25 179.75 181.25 185.75 187.25 191.75 193.25 197.75 199.25 203.75 205.25 209.75 211.25 215.75 217.25 221.75 223.25 227.75 229.25 233.75 235.25 239.75 241.25 245.75 247.25 251.75 253.25 257.75 5–10 2715 User Manual...
  • Page 121 403.25 407.75 409.25 413.75 415.25 419.75 421.25 425.75 427.25 431.75 433.25 437.75 439.25 443.75 445.25 449.75 451.25 455.75 457.25 461.75 463.25 467.75 469.25 473.75 475.25 479.75 481.25 485.75 487.25 491.75 493.25 497.75 499.25 503.75 505.25 509.75 5–11 2715 User Manual...

  • Page 122: Table 5-5: Hrc

    631.25 635.75 637.25 641.75 643.25 647.75 Table 5–5: HRC Channel Visual Carrier Aural Carrier 54.00 58.5 60.00 64.5 66.00 70.5 72.00 76.5 78.00 82.5 84.00 88.5 90.00 94.50 96.00 100.50 102.00 106.50 108.00 112.50 114.00 118.50 5–12 2715 User Manual...
  • Page 123 288.00 292.50 294.00 298.50 300.00 304.50 306.00 310.50 312.00 316.50 318.00 322.50 288.00 292.50 294.00 298.50 300.00 304.50 306.00 310.50 312.00 316.50 318.00 322.50 324.00 328.50 330.00 334.50 336.00 340.50 342.00 346.50 348.00 352.50 354.00 358.50 5–13 2715 User Manual...
  • Page 124 468.00 472.50 474.00 478.50 480.00 484.50 486.00 490.50 492.00 496.50 498.00 502.50 504.00 508.50 510.00 514.50 516.00 520.50 522.00 526.50 528.00 632.50 534.00 538.50 540.00 544.50 546.00 550.50 552.00 556.50 558.00 562.50 564.00 568.50 570.00 574.50 5–14 2715 User Manual...

  • Page 125: Table 5-6: Irc

    67.25 71.75 73.25 77.75 79.25 83.75 85.25 89.75 91.25 95.75 97.25 101.75 103.25 107.75 109.25 113.75 115.25 119.75 121.25 125.75 127.25 131.75 133.25 137.75 139.25 143.75 145.25 149.75 151.25 155.75 157.25 161.75 163.25 167.75 169.25 173.75 5–15 2715 User Manual...
  • Page 126 325.25 329.75 331.25 335.75 337.25 341.75 343.25 347.75 349.25 353.75 355.25 359.75 361.25 365.75 367.25 371.75 373.25 377.75 379.25 383.75 385.25 389.75 391.25 395.75 397.25 401.75 403.25 407.75 409.25 413.75 415.25 419.75 421.25 425.75 427.25 431.75 5–16 2715 User Manual...
  • Page 127 541.25 545.75 547.25 551.75 553.25 557.75 559.25 563.75 565.25 569.75 571.25 575.75 577.25 581.75 583.25 587.75 589.25 593.75 595.25 599.75 601.25 605.75 607.25 611.75 613.25 617.75 619.25 623.75 625.25 629.75 631.25 635.75 637.25 641.75 643.25 647.75 5–17 2715 User Manual...
  • Page 128 2715 assumes that the test signal in the specified line is spectrally flat at the head end. If this is not true, the 2715’s flatness will be misstated. A technique for assessing flatness and compensating for a nonflat video source is suggested in the section on ICR measurement details.
  • Page 129 1st mixer of the 2715. In this case, the 2715 automatically increases the 1st mixer input level (by the minimum amount required).

  • Page 130: Carrier Level And Averaged Power Measurement

    CATV Measurements The 2715 is designed so that you will always have a choice of whether or not you use gated (in-service) measurement techniques. If you follow the In-Service menu selections for C/N, CSO, or ICR, you will be making a gated measure- ment;...
  • Page 131 CARRIER LEVEL When the CARRIER LEVELS measurement is initiated on an analog channel, the 2715 performs the following steps that are common to all CARRIER LEVELS measurement modes: H Recalls base settings, if necessary. Base settings are the standard settings from which each test is run;...
  • Page 132 AVERAGED POWER If you measure a digital channel, the 2715 executes these steps for each carrier: H Recalls base settings, if necessary. Base settings are the standard settings from which each test is run; equivalent to selecting [0] (RECENTER...
  • Page 133 7. Press [0] to run the Carrier Levels measurement, using the accurate frequency and amplitude mode. After completing the measurement, the instrument displays the current results superimposed on the spectral display. 8. Press [CATV/APPL] to again display the CARRIER LEVEL -- AVG POWER menu. 5–23 2715 User Manual...

  • Page 134: Figure 5-4: Carrier Level, Averaged Power Measurement Results

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.

  • Page 135: Carrier Survey Measurement

    H Intercarrier frequency (not available when measuring a digital channel) H Visual-to-aural carrier amplitude ratio (not available when measuring a digital channel) When the CARRIER SURVEY measurement is initiated, the 2715 performs the following steps: H Advances to the next unskipped channel in the channel table H Executes a CARRIER LEVELS measurement (refer to Carrier Levels Measurement on page 5–20), using the measurement mode selected for...
  • Page 136 3. Press [CATV/APPL] [8] [2] to skip the selected channel. Another way to skip channels is through the IBM-compatible PC software that is provided as an accessory. Refer to the Cable TV RF Measurements Software for Windows manual for more information. 5–26 2715 User Manual...

  • Page 137: Figure 5-5: Typical Carrier Survey Report Screen

    [Z]. After all of the current results have been displayed (as you continue pressing [W] or if you press [Z]), the 2715 starts displaying stored results for the Carrier Survey measurement beginning with the last stored results. After all the results have been displayed, the 2715 reverts to the CARRIER SURVEY menu.

  • Page 138: Modulation Depth Measurement

    Test results can be displayed and stored. Stored or current results can be printed if you have an RS-232 interface installed in the 2715 You make selections and run the modulation depth test using the CATV MEASUREMENTS submenu, MODULATION DEPTH, which provides...
  • Page 139 Now you can choose to either view other previously stored results for this measurement by pressing [W], or stop viewing the results by pressing [Z]. 8. Press [Z] to return to the MODULATION DEPTH menu. 5–29 2715 User Manual...
  • Page 140 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.

  • Page 141: Table 5-7: Examples Of Cycle Delay/Target Line Duration Interaction

    H Current Sync Tip Voltage—value appears in the upper left hand corner of the display. If the sync tip voltage varies during the adjustment process, the 2715 automatically adjusts the reference level to keep the sync tips at the top of the screen and displays the new sync tip voltage value.

  • Page 142: Aural (Fm) Deviation Measurement

    Test results can be displayed and stored. Stored or current results can be printed if you have an RS-232 interface installed in the 2715. NOTE. This measurement has no meaning for channels in which the aural carrier uses AM modulation.
  • Page 143 This mode can be used in System Test Programs, since it does not require user interaction. When you initiate an auto FM deviation measurement, the 2715 does the following: 1. Checks if the channel table specifies this channel as TV or FM. If the channel is specified other than TV or FM, the measurement is aborted.
  • Page 144 CATV Measurements 3. Prompts you to either resume or accept the current measurement. If you select RESUME, the 2715 makes another measurement. The min hold register is not cleared between measurements to allow further accumulation of the peak deviation. Adjustment Mode...

  • Page 145: Carrier-To-Noise, Desired-To-Undesired Measurement

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 146 300 kHz with no video filter, span to 200 kHz/div, sweep speed to 50 ms/div (200 ms/div if the modulation polarity is positive as in the French L system). The 2715 makes a single sweep, and then does a peak search with the marker and records the marker value as the carrier level.

  • Page 147: Table 5-8: Locations Of Noise Measurement

    NOTE. The Carrier-to-Noise test result may be marked with an asterisk ( ). This indicates that the measured noise level is within 2 dB of the 2715’s calculated noise level. Under these conditions, the inaccuracy is always on the conservative side;...
  • Page 148 CATV Measurements DESIRED-to-UNDESIRED When the DESIRED-to-UNDESIRED measurement is initiated, the 2715 performs the following: 1. Average power measurements as is done as described in the CARRIER LEVEL -- AVG POWER menu on page 5–23. 2. The user is prompted to turn the channel under test off.
  • Page 149 6. Press [0] to run the CARR/NOISE -- DESIRED/UNDESIRED measure- ment. After the measurement is complete, the instrument displays the current results, the offset frequency (from the carrier) at which the noise was measured, and the normalization bandwidth superimposed on the spectral display. 5–39 2715 User Manual...

  • Page 150: Hum/Lfd Measurement

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 151 The time domain data is displayed in waveform B. Enable HUM/LFD The following procedure shows how to make a HUM/LFD measurement: Measurement 1. Press [CATV/APPL] to call up the CATV MEASUREMENTS menu. See Figure 5–1. 2. Press [6] to select the HUM/LFD measurement menu. 5–41 2715 User Manual...
  • Page 152 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.

  • Page 153: Frequency Response

    If a valid reference exists, the mode 1 test (WITH REF) may be run. The first step is to recall the reference settings into the 2715 hardware. Then after each sweep, the raw sweep data is filtered using the identical digital filter used to filter the reference data.
  • Page 154 3. Press [5] [0] [BKSP] [0] to run the frequency response measurement without a reference. The instrument sets the 2715 to sweep between the specified start and stop frequencies with a 5 MHz resolution bandwidth and returns to normal user control.

  • Page 155: Figure 5-6: Typical Frequency Response Display Without Reference

    To acquire a frequency response reference, perform the following steps: 1. Press [CATV/APPL] [5] to call up the FREQ RESP SETUP menu. 2. Press [1] to select the “WITH REF” test mode. 5–45 2715 User Manual...

  • Page 156: Figure 5-7: Typical Frequency Response Display With Reference

    Figure 5–7. 133.3MHZ M 108.6MHZ 22.2DBMV/ M 16.5 DBMV 15.6MHZ/ 5DB/ 5MHZ RBW STD CH 8 FRQ RESP: ”W” OR ”Z” TO QUIT CHAN Figure 5–7: Typical Frequency Response Display With Reference 5–46 2715 User Manual...

  • Page 157: Adjacent Channel Leakage Measurements

    If any coherent spurious signals are found in the adjacent channels, the largest is reported to the instrument screen, but is not stored as part of the results. The 2715 assumes that the adjacent channel is of the same type as the channel under test.
  • Page 158 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.

  • Page 159: Ctb And Cso Measurements

    NOTE. The CTB or CSO test result may be marked with an asterisk ( ). This indicates when a beat signal is within 2 dB of the 2715’s noise level. Under these conditions, the displayed dBc value may be lower than the actual value (that is, the beats may have a smaller amplitude than the displayed value).
  • Page 160 NCTA-recommended settings (span at 50 kHz/div, RBW to 30 kHz, and video filter to 10 Hz). The 2715 may adjust the reference level so that the reading is at least one division from the bottom of the screen to minimize logging errors.
  • Page 161 The interval at which the continuous CSO repeats is selectable from 15 seconds (default) to 21600 seconds (6 hours) in one second increments. The 2715 periodically runs a subset of normalizations throughout the test. These normalizations take about 3 minutes. The interval is selectable from 1 hour (default) to 24 hours in one hour increments.
  • Page 162 After one cycle of the test is complete, it waits for the test interval to expire, then repeats the test. During the test, the 2715 display shows the current time, the time when the next cycle will start, the time when the complete test will finish, and the time the next normalization will occur.
  • Page 163 You can also view those results with the DISPLAY RESULTS selection. Each time a measurement is made, the instrument displays the worst case result up to that point. 10. Press [CATV/APPL] to display the CTB or CSO menu. 5–53 2715 User Manual...

  • Page 164: Figure 5-8: Typical Ctb (Or Cso) Measurement Results Display

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 165 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 166 A display resembling Figure 5–8 comes up. You can either view other previously stored results by pressing [W], or stop viewing the results by pressing [Z]. 13. Press [3] to print the results of the last measurement performed. A printer must be connected to the 2715. 5–56 2715 User Manual...
  • Page 167 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 168 Next it measures the amplitudes of the beats within 50 kHz on either side of the specified beat frequencies. It then waits for the interval to expire so the cycle can be repeated. 5–58 2715 User Manual...

  • Page 169: Figure 5-9: Typical Continuous Mode Results Display

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.

  • Page 170: Cross Modulation Measurement

    The Frequency Domain method reliably detects sidebands arising from either amplitude modulation or phase modulation (or a combination of both). Also, the useful measurement range of the Frequency Domain method is significantly greater than that of the Time Domain method. 5–60 2715 User Manual...
  • Page 171 METHOD (FREQUENCY DOMAIN or TIME DOMAIN (NCTA)) LEAVE CROSS MODULATION 3. Press [5] to select the method for measuring the cross modulation. (Refer to CROSS MODULATION Measurement on page 5–60 for information about the measurement methods.) 5–61 2715 User Manual...

  • Page 172: In-Channel Response Measurement

    NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer or long jobs may not print completely.
  • Page 173 20 of field 1 and line 9 through line 19 of field 2. However, the 2715 counts field lines consecutively from 1 to 525. Therefore, the range of potentially valid line numbers for the test signal will be 10 through 20 (for odd-numbered fields) or 272 through 282 (for even-numbered fields).
  • Page 174 When using a multiburst generator, you must enter the frequencies that it actually produces. If you are not sure which frequencies your generator produces, consult your generator manual, or use the 2715 to measure them. Do not use the 2715 count function to measure the multiburst frequencies. It may not produce accurate results on burst and pulsed signals.
  • Page 175 3. Press [5] [0] to select the Interactive mode. 4. Press [BKSP] [0] to run the measurement. If you are not running the test in-service, the instrument pauses and prompts you to enable a full-field test signal (Multiburst or Line Sweep). 5–65 2715 User Manual...
  • Page 176 NOTE. You can print measurement results only when the RS-232 interface is installed in the 2715. The GPIB interface does not support the print function. Be sure to select handshaking ([UTIL] [4] [0] [2] [5]) to match that expected by the printer.
  • Page 177 11. Press [2] to display the results of the last measurement performed. A display resembling Figure 5–8 on page 5–54 appears. You can view other previously stored results by pressing [W] or stop viewing the results by pressing [Z]. 5–67 2715 User Manual...

  • Page 178: Auxiliary Operations

    When the operation is invoked, the 2715 tunes to the visual carrier and enables the 1 MHz resolution bandwidth filter and zero span. The 2715 then finds and centers the peak of the visual carrier and places it at the reference level. The display storage and readouts are turned off, and short holdoff is selected for an analog display.
  • Page 179 This operation allows you to view one line of demodulated video for the current channel in the analog mode. The setup is the same as for field modulation except that the 2715 sets the sweep time to 10 µs/div and the trigger mode to TV Line trigger.
  • Page 180 You can disable the LISTEN mode by pressing [CATV/APPL] [4] again or [DEMOD] [0]. However, if you use the [DEMOD] [0] selection to disable LISTEN mode, the active channel will not be recentered on the screen — you merely turn off demodulation. 5–70 2715 User Manual...

  • Page 181: Spectrum Analyzer Menus

    Spectrum Analyzer Menus...

  • Page 183: Using The Menus

    Spectrum Analyzer Menus This section describes the menu-selected, firmware-driven features of the 2715. The menus provide a high degree of sophistication without a complicated control panel. Press any key in the front-panel MENU function block to cause a menu to be displayed on the screen.

  • Page 184: Figure 6-1: The Input Menu

    At each step, the new status appears at the end of the line. H If the 2715 accepts a smaller range of values, it presents a secondary menu consisting of a list of the values that may be selected by pressing their corresponding keypad keys.
  • Page 185 In general, menus are not reproduced here. It is intended that you call up menus on the 2715 and follow along with the examples in this section as they are described. For a handy reference, consult Operating Basics.

  • Page 186: Input

    5. Press [INPUT] [9] once again to turn the calibrator back on. Setting RF Attenuation The following steps show how to set the RF attenuation. 6. Press [REF LEVEL] [4] [8] [] [8] [Y] to set the reference level to 48.8 dBmV. 6–4 2715 User Manual...
  • Page 187 8. Reset the reference level to 48.8 dBmV and select the INPUT menu. Item 5 indicates that the RF attenuation is 30 dB and that it is selected automati- cally by the 2715. We can control the RF attenuation so that it remains at a fixed value.
  • Page 188 A list of six possible units appears. Select item 2, dBV. The spectral display is restored, but the reference level now reads –41.2 dBV because 1 mV is 60 dB below a 1 V reference. Only the units change, not the 2715 gain, attenuation, or input impedance. Therefore, the displayed spectrum is unchanged.
  • Page 189 32. Enter a value of 0 dB for external attenuation. Accommodating a 50 W The 2715 has a 75 W input impedance and expects a 75 W signal source impedance. However, a 50 W source impedance is typically associated with some Source applications that use dBm as a standard amplitude measurement unit.
  • Page 190 In this case, you select the dBm unit via [INPUT] [3] [0] and the 50 W source because the 2715 is matched to the 75 W side of the minimum loss pad and the signal really is being terminated in a 50 W impedance. Further, it is the attenua- tion of the pad that is entered under item 6 and not its insertion loss.
  • Page 191 The 2715 has automatically reduced its internal gain (thus lowering the normal noise floor) to compensate for the added gain of the preamplifier. The result is that you can now see signals that are up to 12 dB below the normal 2715 noise floor. Toggle the preamplifier off.
  • Page 192 The signal intensity is read out on screen using the marker and corrected for distance, in either dBmV/m or V/m. Using the DISPLAY menu, you can have the 2715 sound an alert if the measured signal exceeds a threshold that you set. This feature facilitates go/no-go or present/absent tests.
  • Page 193 If possible, measure the return loss of the antenna to make certain it is properly tuned to the desired frequency. See Tektronix application note 26W-7037-1, Spectrum Analyzer Fundamentals, concerning return loss measurements.

  • Page 194: Table 6-1: Equivalent Decibel - Voltage Values

    5. Enter the distance at which the measurement will actually be carried out (default distance is 3.0 m). You can enter distances in feet, meters, kilometers, or miles, but the 2715 converts them to meters or kilometers before displaying them.
  • Page 195 If you wish to enter new antenna data or change old data, use the following procedure: 1. Press [INPUT] to call up the Input menu. 2. Press [9] to select DBUV/M SETUP from the INPUT menu. 3. Press [0] to select item EDIT ANTENNA TABLE. 6–13 2715 User Manual...
  • Page 196 A list of frequencies beginning with the start frequency and ending with the stop frequency appears. The numbers to the right of the frequencies are the antenna factors, or K-factors. When creating antenna tables, the 2715 supplies default values of zero for the K-factors.
  • Page 197 13. Press [Y] to delete an old name entirely. (You can press [Z] to abort the title editing process without changes.) 14. Turn the FREQ/MKRS knob to select letters to change the title. 15. Use MKR [ ' ] or MKR [ a ] to move the cursor back and forth. 6–15 2715 User Manual...
  • Page 198 After you delete the original, store the edited version in the original location. You can print the antenna data if your 2715 is equipped with an optional communications port and appropriate printer. 19. To print the antenna data, select item 5, PRINT, from EDIT ANTENNA TABLE.

  • Page 199: Mkr/Freq

    Perhaps you would prefer to directly specify the beginning and ending frequen- Frequencies cies of the display rather than its center frequency and span. The 2715 enables you to do so as follows: 1. Press [MKR/FREQ] [7] to call up the Marker/Frequency menu.
  • Page 200 If you are not in the delta-marker mode when you select MARKER START/STOP, the 2715 will enter zero span at the current center or marker frequency.
  • Page 201 DC (delta count). 9. Repeat this procedure for the third harmonic. Notice that although the reference peak (the cal signal fundamental) is now far off-screen to the left, you are still accurately measuring the difference frequency. 6–19 2715 User Manual...
  • Page 202 Marker/Frequency menu, item 2 also conveniently turns on the marker mode when it is set to MKR. If you trigger the 2715 with a TV video sync pulse by choosing KNOB SELECTABLE from the Sweep/Trigger menu Setup Table, the Knob Function menu offers another choice: VIDEO LINE.
  • Page 203 1. Call up the Marker/Frequency menu. Item 8 is a two-way toggle function indicating that the tuning increment is presently being automatically selected by the 2715. In AUTO mode, the tuning increment is as shown in Table 6–2. 6–21...

  • Page 204: Table 6-2: Auto Tuning Increment

    SF (as in SF 300MHz) indicating that the start frequency is now 300 MHz. Some users prefer to run the 2715 in this mode. This feature can be useful for viewing sidebands or performing harmonic distortion measurements.
  • Page 205 12. Press any menu button to return to the spectral display. Counter Resolution The 2715 enables you to change the resolution of its built-in counter. It is possible to specify its resolution as 1 kHz or 1 Hz, or to turn off the counter when the Signal Track mode is in use.
  • Page 206 The current center frequency is approximately 300 MHz (as would be the start frequency if you placed the 2715 in that mode). 2. Press [0] to select the center frequency as the tuning increment.
  • Page 207 18. Turn the FREQ/MKRS knob. The frequency changes by 7 MHz per click, a value not otherwise available. Entering a keypad tuning increment automatically places the 2715 in programmed tuning mode. 19. There are two ways to turn off any programmed increment, including the keypad entered increment: a.
  • Page 208 8. Turn on the marker and turn the FREQ/MKRS knob clockwise. The marker frequency is also increased by 5.15 GHz. 9. Press [MKR/FREQ] to call up the Marker/Frequency menu. 10. Press [9] to select the SETUP TABLE. 6–26 2715 User Manual...

  • Page 209: Dspl

    H Change the source of the display from an internal to an external signal H Control an on-screen reference line to simplify amplitude measurements and establish alarm thresholds H Enable and disable the Min Hold feature 6–27 2715 User Manual...

  • Page 210: Ensemble Averaging

    Spectrum Analyzer Menus Changing the Display You can place the 2715 in the analog display mode by turning off all the display Mode registers using [A], [B], [C], and [D] (see Display Storage on page 4–20). However, a more convenient method when two or more registers are active, is to use item 0 on the Display menu.
  • Page 211 You can also stop the averaging by selecting item 2 from the menu. Continuous averaging weights older sweeps so that they have a progressively smaller effect on the average. Each step back in time reduces the impact of a sweep to 90 per cent of its previous value. 6–29 2715 User Manual...
  • Page 212 The spectral display reappears and both status indicators for register A light. At the bottom of the right-hand readout column, the number of sweeps averaged is displayed (displayed only when the 2715 is in the non-CATV mode). When all 24 sweeps have been included in the average, the readout stops indicating the number unless the A register is the only one turned on.
  • Page 213 The mean spectrum leaves little doubt as to the presence or location of the signal peak. Sometimes you can achieve even better results using the average minimum. 40. Experiment if you like before proceeding, then clear the A, B, and C registers and leave only the D register active. 6–31 2715 User Manual...
  • Page 214 In your instrument the noise floor may rise slightly with increasing frequency. 1. Perform a 24 sweep MAX/MIN ensemble average and store the result in A. The average indicator is displayed only when the 2715 is in the non-CATV mode. 2. Wait until the ensemble average is complete.
  • Page 215 The technique works no matter the direction of the signal change. 8. Reset the reference level to 18.8 dBmV and change the center frequency slightly. Again the calibration signal peaks appear. Any change from the average, either amplitude or frequency, becomes obvious. 6–33 2715 User Manual...
  • Page 216 See Figure 6–7. 15. Press [DSPL] [3]. The waveform is now nearer the bottom of the screen where you can see it more clearly. 6–34 2715 User Manual...
  • Page 217 400MHZ ATTN 0DB 18.8DBMV VF WIDE 100 . 0MHZ/ 10 DB/ 5MHZ RBW Note the signal peaks are no longer folded. FREQ CALIBRATOR Figure 6–8: B, C Minus A Offset to Top 6–35 2715 User Manual...
  • Page 218 Notice that the display PEAK is essentially the top of the MAX/MIN display. The 2715 produces an analog spectrum. In the MAX/MIN acquisition mode, the maximum and minimum amplitudes of this spectrum are alternately sampled at 512 successive points. Plotting the two interleaved sets, of 256 points each, produces the analog-like MAX/MIN spectrum that you see.
  • Page 219 As an example, the following procedure creates a new title, TEST123: 3. Press [2] to start the title mode edit. 4. Rotate the FREQ/MKRS knob until the letter T appears. 5. Press MKR [ ' ] to move the cursor one place to the right. 6–37 2715 User Manual...
  • Page 220 16. Press [DSPL] [5] [4] to select PLOT LABELING EDIT. Since plot labels can use all 16 display lines instead of just one, most of the instructions are on a separate screen so that they do not cover the label being entered. 6–38 2715 User Manual...
  • Page 221 Turning Graticule Item 6 on the Display menu is a simple toggle that turns the graticule illumina- Illumination On and Off tion on and off. Press [DSPL] [6] several times to see the graticule illumination change states. 6–39 2715 User Manual...
  • Page 222 The signal must be input to the 2715 on pin 1 of the rear panel Accessory Connector J103, and must be in the range of 0 to 1.4 V with a 3 dB bandwidth of 50 kHz or less.
  • Page 223 Spectrum Analyzer Menus 3. Press [2] [] [2] [Z] to enter –2.2 dBmV. The 2715 reverts automatically to the spectral display that now contains a horizontal line two divisions down (–2.2 dBmV). You will notice the A register red LED is lit. When you display the line, you cannot display the contents of the A register.
  • Page 224 The following procedure describes how to determine the approximate upper and lower bounds on a spectrum by using the MIN HOLD and MAX HOLD features. While MAX HOLD is accessible by dedicated key, MIN HOLD can be accessed only from the Display menu. 6–42 2715 User Manual...

  • Page 225: Appl

    30KHz RBW (AUTO) CALIBRATOR This menu is not accessible when the 2715 is in the CATV mode. (When the 2715 is in the CATV mode and [CATV/APPL] is pressed, the CATV Measure- ments pages come up on the screen.) Disable the CATV mode by pressing [CATV/APPL] [8] [0].
  • Page 226 One of the items (SIGNAL SEARCH) enables the 2715 to automatically detect and catalog any signals within a specified frequency range and above a desig- nated threshold.
  • Page 227 10 DB/ 5MHz RBW (AUTO) Item 2 of the Applications menu causes the 2715 to measure the average noise at the marker location and normalize it to a specified bandwidth. The default bandwidth is 4 MHz, but you can change it to suit your application.
  • Page 228 Notice that the noise amplitude readout does not change significantly. The noise amplitude appears to be approximately halfway between the maximum and minimum values of the spectral display. This is because the 2715 does not compute the arithmetic mean of the minimum and maximum values using decibels (that yields an incorrect answer).
  • Page 229 The spectral display reappears with the fixed marker on top of the 100 MHz signal peak (the 2715 places the fixed marker on the signal peak nearest the center of the screen in the C/N mode). The moveable marker appears 1 division from the left screen edge.
  • Page 230 Notice the measured noise is approximately –42 dBmV. If we connected the 2715 to a cable television tap with a 0 dBmV video signal and a 43 dB C/N, we would be unable to measure the noise or C/N because the cable noise (–43 dBmV in this example) is below the normal 2715 noise floor.
  • Page 231 10xSPAN/ 10xSPAN/ Note the SPAN/DIV overlap of each search range. Figure 6–10: The SIGNAL SEARCH Frequency Range To see how SIGNAL SEARCH works, reset the following 2715 controls to search the frequency range from 55 to 550 MHz. SPAN/DIV 5.0MHz RESOLUTION BW 300.0KHz...
  • Page 232 10 DB/ 5MHz RBW (AUTO) Measuring occupied bandwidths is similar to measuring signal bandwidths, except that the 2715 determines the bandwidth that contains n% of the signal’s energy rather than the bandwidth enclosed by the x dB down points. 6–50...
  • Page 233 Spectrum Analyzer Menus To determine the occupied bandwidth, the 2715 first sums the signal power in all 512 frequency cells of the displayed spectrum, ignoring any contributions more than 40 dB below the signal peak. (This is the total displayed signal power, P...
  • Page 234 You can demonstrate occupied bandwidth mode using a broadcast signal: 1. Connect a short antenna or CATV tap to the 2715 input as outlined in Appendix B: Broadcast AM, FM, and TV Signal Sources.
  • Page 235 — a resolution bandwidth filter that is too wide will artificially broaden the occupied bandwidth (remember how the 5 MHz resolution bandwidth filter made the calibrator signal look like it is 5 MHz wide) H Only vertical scales of 5 or 10 dB/div can be used 6–53 2715 User Manual...
  • Page 236 10 DB/ 300KHz RBW (AUTO) Normally, the display you see on the 2715 represents the input signal after it has been AM detected. The result is a conventional spectral display of signal power vs. frequency. However, by selecting FM DEVIATION MODE, you can view instantaneous frequency variations vs.
  • Page 237 The following steps show how to read out the frequency deviation with the marker: 9. Press [MKR/∆/OFF] to turn the marker on. 10. Turn off all registers except register A. 11. Use the FREQ/MKRS knob to move the marker to the point where you want the measurement. 6–55 2715 User Manual...

  • Page 238: Demod

    Listening to signals often helps to identify the source. A built-in speaker is Transmissions provided, but if higher fidelity is needed, or if you are using the 2715 in a noisy location, headphones can be used. A 1/8 inch miniature phone jack is located near the front of the right side of the 2715.
  • Page 239 8. Press [ZERO SPAN] to hear whatever is being transmitted by the station. 9. Leave the 2715 in zero span, and turn the FREQ/MKRS knob to tune it as you would a radio receiver. The signal level rises as you tune in stations and falls to the noise floor when no station is present.
  • Page 240 Spectrum Analyzer Menus 21. Leave the 2715 in zero span, and turn the FREQ/MKRS knob to tune it as you would a radio receiver. The signal level rises as you tune in stations and falls to the noise floor when no station is present.
  • Page 241 5. Press [DEMOD] to return to the spectral display. 6. Ensure that the calibrator is turned off. 7. Connect a short antenna or CATV tap to the 2715 input as outlined in Appendix B: Broadcast AM, FM, and TV Signal Sources.

  • Page 242: Util

    2715 is to be configured. The following example uses the Utility menu to reset the center frequency, reference level, and span. You could also set the resolution BW, video filter, vertical scale, and sweep rate.
  • Page 243 3 kHz, 10 kHz, 30 kHz, 100 kHz, 300 kHz, 1 MHz, or 5 MHz — if you enter another value, the 2715 will convert it to the nearest available value H This menu provides the only method of manually setting the video filter bandwidth.
  • Page 244 Spectrum Analyzer Menus Save and Recall Settings The 2715 enables you to save and recall up to 36 sets of control settings and any and Displays saved displays that accompany them. These are in addition to the factory default power-up settings that are permanently stored in the instrument. The 2715 also automatically saves the settings/displays in use (in location 0) when it is powered down.
  • Page 245 At power-up the 2715 restores the user-defined power-up settings, if they exist, following the standby period. If they do not exist, it uses the factory default settings. If the user-defined power-up settings include a narrow span, the NORMALIZATION SUGGESTED message may appear.
  • Page 246 CANNOT OVERWRITE SAVED DISPLAY message is displayed when you try to recall settings.) 23. Press [MAX HOLD] to turn it off. 24. Press [UTIL] [1] [2] [W] to reinitialize the 2715 to your user-defined power-up settings. 25. Press [UTIL] [1]. Item 3 reads as follows: AB 90MHZ 38.8DBMV 20MHZ...
  • Page 247 NVRAM should ever be lost is described later in Service Normalizations on page 6–80. If the 2715 self-test routine detects that the present 2715 gain or frequency characteristics differ significantly from those determined during the previous normalization, the NORMALIZATION SUGGESTED message is displayed on the screen.
  • Page 248 If you must make measurements immediately after the instrument is turned on and the NORMALIZATION SUGGESTED message is on screen, carry out a normalization directly. Note, however, that if you do so, the 2715 may require renormalization after it is fully warmed up.
  • Page 249 1. Press [UTIL] to call up the Utility menu. 2. Press [4] to select SYSTEM CONFIGURATION. Configuring the The 2715 is provided with a digital communications port to exchange data and Communications Port commands with an external instrument controller or a printer/plotter. Either an RS-232 Interface (Option 08) or an IEEE 488 General Purpose Interface Bus (GPIB) port (Option 03) is available.
  • Page 250 4. Press [2] to select RS-232 from the COMMUNICATION PORT CONFIG menu. Several choices are offered; in all cases the 2715 settings must match those used by the controller or printer/plotter. H Item 0, STATUS, enables you to toggle the RS-232 port on and off line. The port must be on-line to communicate with any other device.
  • Page 251 H Item 6, ECHO, is a toggle intended for use with unsophisticated terminals. When ECHO is ON, the 2715 sends the character it has just received back to the terminal screen. CTRL Q and CTRL S are not echoed. The default is OFF.
  • Page 252 The EOI/LF MODE option is included for controllers that do not use the EOI signal line. H Item 4, TALK ONLY MODE, must be set to OFF when the 2715 is used with a controller, because the controller determines whether the 2715 is talking or listening.

  • Page 253: The Audio Alert

    RS-232 interface is installed in your instrument). If the GPIB option is installed, CRT is always displayed. Select CRT if you want results that would normally be sent to a printer to be displayed on the 2715 screen instead. On-screen display is sometimes not satisfactory if there is more than one screen of data, because only the last screen remains visible.
  • Page 254 Spectrum Analyzer Menus H ERROR ONLY — This is the factory default. A beep occurs only when the 2715 issues an alarm, error, or warning message. The alert sounds only once, even if the condition repeats and a displayed message is repeated.
  • Page 255 CALIBRATOR During normal operation, the 2715 periodically computes frequency corrections (to compensate for short-term drift within the 2715 itself) and applies them to the displayed trace. It does this between sweeps. You can shorten the intersweep interval by disabling the frequency corrections, although some high-frequency accuracy may be sacrificed, and the signal may drift off screen at small spans/div.
  • Page 256 The SWEEP HOLDOFF status switches from NORMAL to SHORT HOLDOFF and a signal peak may appear at the left edge of the screen. 14. Press [7] to reset the sweep holdoff to NORMAL. 15. Press [6] to turn off SPECTRAL DISPLAY IN MENUS. 6–74 2715 User Manual...
  • Page 257 8. Press [UTIL] to return to the spectral display. The File System The 2715 stores settings, waveforms and other data in a system of files in NVRAM. Normally you will not alter those files. Press [UTIL] [4] [6] to view a directory of existing file names.

  • Page 258: Table 6-3: The File System

    CHTBL0 – CHTBL9 RSLTX FCOR NORM Table 6–4: Additional File System Name Description 12.88 Version SEARCH Signal search configuration SETUP Instrument configuration S_CATV CATV configuration S_GPIB GPIB configuration S_PLOT Plotter configuration S_RTC Real-time clock configuration S_TTYx RS-232 configuration 6–76 2715 User Manual...
  • Page 259 Spectrum Analyzer Menus DSET00 and SET0BU are special files. They are created automatically by the 2715 and contain the D-register settings used when the 2715 was last turned off. SET0BU is a backup in case DSET00 is corrupted during a power-down or power-up cycle.
  • Page 260 NOTE. Any control settings can be used. Adjustments Many of the items on the Utility menu are intended for servicing of the 2715. However, we will describe a few used to verify instrument performance. Items not discussed are reserved for service personnel or for use under factory supervision.
  • Page 261 Spectrum Analyzer Menus settings other than the factory default of 5000 ms must be made by the user of the specific 2715 spectrum analyzer. The best way to verify operation is to compare measurement results using the factory-default YIG oscillator settling delay time and your reset time.
  • Page 262 Spectrum Analyzer Menus Service Normalizations The 2715 contains a set of frequency and amplitude normalization values when it is shipped from the factory. The normalizations are based on reference values, called reference normalizations, determined at the time of manufacture. The reference normalizations specify the 2715 gain step sizes and the frequency and amplitude of the internal calibrator signal.
  • Page 263 These can be handy for future reference. Item 6 sends any messages that occur during normalization to the printer. If your 2715 has RS-232 installed, you can obtain a hard copy of the normaliza- tion values by doing the following: 10.
  • Page 264 [UTIL] [3] [0]. The 2715 will be useable, but the references should be renormalized at the earliest opportunity. If the battery is worn out, you will have to renormalize the 2715 each time it is used until the battery can be replaced.

  • Page 265: Swp/Trig

    Just as on a conventional oscilloscope you can choose the input signal, an Modes external signal applied at the back panel of the 2715, or the AC power line as the trigger source. You do this by selecting INTERNAL, EXTERNAL, or LINE trigger from the SWP/TRIG menu.
  • Page 266 LEVEL control (inner knob to the left of SWP/TRIG). If the 2715 is placed in zero span and linear amplitude mode, the resulting waveforms resemble those that you would see on an oscilloscope (detected signal amplitude vs.
  • Page 267 The External trigger signal is applied through a BNC connector (J102) on the back of the 2715; its amplitude can be from 100 mV to 50 V. See Appendix E: External Input and Output for additional information.
  • Page 268 The screen should resemble Figure 6–16. In CONTINUOUS mode, the sweep generator is triggered by the first pulse that occurs after the 2715 enters the ready-to-be-triggered state. In other words, after the 2715 completes the current sweep, it enters the ready-to-be-triggered state, and is retriggered by the first horizontal sync pulse that comes along.
  • Page 269 This signal is usually present between lines 15–20 in the U.S. (see Figure 6–17). The display is not as bright as it was in the CONTINUOUS mode, because the 2715 is triggering on, and displaying, only one horizontal line out of every 525. If the display is too dim, adjust the INTENSITY control.
  • Page 270 15. Call up the Sweep/Trigger menu and choose item 6, SWEEP RATE. 16. Following the prompt, enter 5 ms/div. The 2715 reverts immediately to the display mode and you can see three whole video frames. This feature enables you to conveniently set sweep rate when you are already working in the Sweep/Trigger menu and may have turned off the readouts.

  • Page 271: User Def

    This feature enables you to carefully examine a small portion of the spectrum. It is also convenient for manually scanning a broadcast or communications band while listening to demodulated signals — the 2715 acts like a radio receiver. The operator can stop at any station since the sweep is being manually controlled.
  • Page 272 6. Run a CARRIER LEVELS measurement on the selected channel. 7. Store the current CARRIER LEVELS measurement results in NVRAM. 8. Repeat steps 4 through 7 for the other nine channels. 9. Press [USER DEF] [9] [9] to select TIME DELAY SETUP. 6–90 2715 User Manual...
  • Page 273 UDP was being defined. If you want to retain only the data from the 24-hour test, be sure to remove all stored results prior to executing the UDP. Also, the SITE and OPERATOR NAMES should be defined prior to the UDP execution so the stored data will be properly nomenclated. 6–91 2715 User Manual...
  • Page 274 Spectrum Analyzer Menus 6–92 2715 User Manual...
  • Page 275 Appendices...
  • Page 277 Supplemental Information is not guaranteed and may not be supported by a performance check procedure. Changes to a characteristic because of the addition of an option are included in Table A–7. A–1 2715 User Manual...

  • Page 278: Table A-1: Catv Characteristics

    Configured using Cable TV RF Measurements Software. Dependent on selected channel table. Frequencies above 1.8 GHz are not supported by the Cable TV RF Measurements Software. Dependent on selected channel table. Total input power (all signals included) cannot exceed +70 dBmV. A–2 2715 User Manual...
  • Page 279 Noise density is measured at 2 MHz offset (by default) from visual carrier during quiet lines in the vertical interval, then normalized to 4 MHz BW and expressed as Optimum Input Range See Figure A–1 on page A–7 Maximum Range See Figure A–1 on page A–7 Resolution 0.3 dB A–3 2715 User Manual...
  • Page 280 (flatness) are measured relative to a reference trace (stored during the frequency response reference setup) Reference Trace Storage Up to 10 traces with spectrum analyzer states (Nonvolatile) Range 5 dB/div, fixed Resolution 0.2 dB Trace Flatness Accuracy 0.75 dB A–4 2715 User Manual...
  • Page 281 Listen (Typical) The aural carrier for the selected channel is demodulated Output Speaker or headphones with volume control Demodulation Type Sweep Displays instantaneous peak FM deviation Total input power (all signals included) cannot exceed +70 dBmV. A–5 2715 User Manual...
  • Page 282 Standard vertical interval test signal (line sweep, ghost-canceller, multiburst) is measured within gate which excludes active video; result is expressed as dB P-P Resolution 0.2 dB Accuracy 0.5 dB assuming test signal is flat at head end A–6 2715 User Manual...
  • Page 283 –20 –30 –10 Normal limits without preselector and mixer input level set to default setting VISUAL CARRIER PEAK (dBmV) of –30 dBm in a 60 channel flat system. Figure A–2: Typical Accuracy Limits for CTB Measurement A–7 2715 User Manual...
  • Page 284 Normal limits without preselector and mixer input level set to default –30 –20 –10 setting of –30 dBm in a 60 channel flat system. VISUAL CARRIER PEAK (dBmV) Figure A–4: Typical Accuracy Limits for Gated CSO Measurement A–8 2715 User Manual...
  • Page 285 500 MHz to 1000 MHz in 60-channel flat system dominated by analog signals 10 dB stronger than average power of channel under test Measurement Limit (dB) –20 –10 CHANNEL UNDER TEST INPUT LEVEL (dBmV) Figure A–6: Typical D/U Measurement Range Limits for 2 dB Accuracy A–9 2715 User Manual...
  • Page 286 10 dB stronger than average power of channel under test –65 –55 Measurement –45 Limit (dBc) –35 –25 –20 –10 INPUT LEVEL (dBmV) Figure A–8: Typical Digital Signal CTB Measurement Range Limit for 2 dB Accuracy A–10 2715 User Manual...

  • Page 287: Table A-2: Frequency-Related Characteristics

    2 dB 9 KHz to 1.8 GHz and PREAMP off Option 50 and Option 75: 3 dB above Flatness is affected by: 1.8 GHz H Input voltage standing-wave ratio (VSWR) H Gain variation H Mixer conversion A–11 2715 User Manual...
  • Page 288 12 video filters (3 Hz, 10 Hz, 30 Hz, 100 Hz, 300 Hz, 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz, 300 kHz, or WIDE) can be selected from the UTIL menu A–12 2715 User Manual...

  • Page 289: Table A-3: Frequency/Amplitude Related Characteristics

    This is the “Reference frequency and amplitude differences Marker” between markers are readouts preceded by the letter D Accuracy Frequency 1 PPM 10 Hz of the higher marker With both signals counted frequency Amplitude Same as Marker A–13 2715 User Manual...

  • Page 290: Table A-4: Amplitude-Related Characteristics

    Log Mode 1 dB or 10 dB 1–2–5 sequence: 10.83 mV/div to Linear Mode 342.33 mV/div FINE REF LVL STEP Activated 0.2 division per increment Accuracy Dependent on: H Normalizations H Calibrator accuracy H Frequency response A–14 2715 User Manual...
  • Page 291 2.0 dB over the 40 dB range 1 dB/div Mode 1 dB maximum error over the 8 dB range Linear Mode 5% of full scale RF Attenuator Range 0 to 50 dB in 2 dB steps A–15 2715 User Manual...
  • Page 292 Not Specified (–119 dBm) 10 kHz –75 dBmV Not Specified (–124 dBm) 3 kHz –80 dBmV Not Specified (–129 dBm) 1 kHz –85 dBmV Not Specified (–134 dBm) 300 Hz –90 dBmV Not Specified (–139 dBm) A–16 2715 User Manual...

  • Page 293: Table A-5: Input/Output Signal Characteristics

    Caution: Do not apply more than 100 VDC or 100V peak AC to the RF Input 1 dB Compression Point (minimum) +34 dBmV (–15 dBm) With no RF Attenuation and 1 mixer at +19 dBmV (–30 dBm) A–17 2715 User Manual...
  • Page 294 Logic output to Option 05 (External Tracking Generator). CMOS logic levels, typically +3.5 V high, +1.5 V low. Pin 10: 26.38 MHz Input Input from Option 05 (External Tracking Generator); typically a 0.5 V sine wave centered at +3.7 VDC. A–18 2715 User Manual...

  • Page 295: Table A-6: Power Requirements

    RS-232 Option 08 Provides a RS-232 serial interface port at J104 to replace GPIB Option 15 Add a 1 LO output LO Output Level +48.8 dBmV ( 0.0 dBm) At spectrum analyzer frequencies 100 kHz A–19 2715 User Manual...

  • Page 296: Table A-8: General Characteristics

    Amplitude and Accuracy +18.8 dBmV (–30 dBm), 0.3 dB, at 100 MHz, 2 kHz Drift 2 PPM/year 7 ms nominal IF Gate Rise and Fall Times Off Isolation > 60 dB A–20 2715 User Manual...

  • Page 297: Table A-9: Environmental Characteristics

    After storage at temperatures below –15_ C, the instrument may not reset when power is first turned on. If this happens, allow the instrument to warm up for at least 15 minutes, then turn power off for 5 seconds an back on. NVRAM is lost below –10_ C. A–21 2715 User Manual...

  • Page 298: Table A-10: Physical Characteristics

    With Handle 14.2 in (360.68 mm) Without Handle 12.9 in (327.66 mm) Depth With Front Panel Cover 17.5 in (444.50 mm) Without Front Panel Cover 16.85 in (427.99 mm) With Handle Extended 20.1 in (510.54 mm) A–22 2715 User Manual...

  • Page 299: Table A-11: Certifications And Compliances

    CAT II Local-level mains (wall sockets). Equipment at this level includes appliances, portable tools, and similar products. Equipment is usually cord-connected CAT I Secondary (signal level) or battery operated circuits of electronic equipment A–23 2715 User Manual...

  • Page 300: Table A-12: Safety Certification Compliance

    EN61010-1/A1 – Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use Additional Compliance UL3111-1 – Standard for Electrical Measuring and Test Equipment IEC1010-1 – Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use A–24 2715 User Manual...
  • Page 301 Appendix B: Broadcast AM, FM, and TV Signal Sources CAUTION. To prevent damage when connecting signal sources to the 2715, be certain the total signal strength is less than +70 dBmV. If in doubt, check with a broadband RF wattmeter or voltmeter.
  • Page 302 Appendix B: Broadcast AM, FM, and TV Signal Sources B–2 2715 User Manual...
  • Page 303 300HZ FILTER NOT INSTALLED 2715 cannot detect presence of 300 Hz filter. ADDITIONAL NVRAM NOT INSTALLED Occurs when accessing a file located in extended NVRAM if the 2715 cannot detect the presence of the extended NVRAM. AMPL NORM SUGGESTED (VR PIN DAC) Perform amplitude normalization.
  • Page 304 Turn Frequency Corrections ON. The location of this selection is [UTIL] [4] [3]. CANNOT CALC. VERT. SENSITIVITY Perform amplitude normalization. Contact your local Tektronix service center or representative if message persists. CANNOT COUNT (VCO IF) Perform frequency normalization. Either the VCO counter input or the IF counter input failure can cause this error to occur.
  • Page 305 Because of span and display storage inaccuracies, the signal may not be exactly centered in the digital display. COMM PORT NOT INSTALLED 2715 cannot detect the presence of the communications port. COMMAND NOT IMPLEMENTED Feature not installed on this instrument. COUNTER FREQUENCY UNSTABLE Perform normalizations again.
  • Page 306 ENSEMBLE AVERAGE COMPLETE Signifies completion of an ensemble average process. ERROR Firmware error. Contact your local Tektronix service center or representative if message persists. FATAL ERROR IN FILE Firmware/hardware error. Contact your local Tektronix service center or representative if message persists.
  • Page 307 FORMATTING PLOT Downloading plot file to hardcopy device. FREQ OUT OF RANGE (NORMALIZATIONS) Perform frequency normalization again. Contact your local Tektronix service center or representative if message persists. FREQ NORM SUGGESTED (1ST LO) Perform frequency normalization. Contact your local Tektronix service center or representative if message persists.
  • Page 308 FUNCTION NOT AVAIL IN MAX SPAN Signal track mode incompatible with MAX SPAN. Try smaller span. ILLEGAL COMMAND Firmware error. Contact your local Tektronix service center or representative if message persists. ILLEGAL PARAMETER PASSED Firmware error. Contact your local Tektronix service center or representative if message persists.
  • Page 309 Firmware/hardware error. Contact your local Tektronix service center or representative if message persists. LAST PWR DOWN REG CHECKSUM ERR Last power down settings bad; defaults used. Contact your local Tektronix service center or representative if message persists. LEAVE INTERACTIVE MODE FIRST An attempt was made to do something illegal in interactive beats or carrier-to-noise mode, such as run another CATV test or try to invoke a UDP.
  • Page 310 Quiet lines are retrace lines where no modulation is present. The Carrier-to- Noise and Composite Second Order tests use quiet lines to take in-service measurements.The 2715 was unable to automatically find quiet lines to use for the tests. NO REFERENCE DEFINED A function was invoked which requires a valid current reference, but no such reference exists.
  • Page 311 NOISE LEVEL LESS THAN 2DB Measured system noise level is less than 2 dB above the 2715 noise floor. Noise power correction has been made by NOISE NORM’D or C/N mode algorithms in the 2715.
  • Page 312 Appendix C: System Messages NVM CHECKSUM ERROR Nonvolatile memory has been corrupted and consequently re-initialized. Contact the local Tektronix service center or representative if message persists. NVM FRAGMENTATION ERR Firmware/hardware error. Contact your local Tektronix service center or representative if message persists.
  • Page 313 Query attempted on function for which there is no query response. QUIET LINE VERIFICATION FAILED The 2715 was unable to find the quiet line used to take in-service Carrier-to- Noise and Composite Second Order measurements. REAL TIME CLOCK HW FAILURE Firmware/hardware error.
  • Page 314 Appendix C: System Messages SATELLITE VIDEO MNTR NOT INSTLD 2715 cannot sense presence of optional satellite (FM) video detector. SEARCH TERMINATED, MAX SIGNALS Signal search is terminated if it detects more than 50 signals. SELECT TALK ONLY MODE FIRST Screen plot front-panel operation requires the GPIB address mode to be talk only when the plot port is set to GPIB.
  • Page 315 The current combination of start/stop/increment setup frequencies results in a correction table with too many elements. TIMER INTERRUPT FAULT Firmware/hardware error. Possible malfunction of interrupt timer on processor board indicated. Contact your local Tektronix service center or representative if message persists after normalization. C–13 2715 User Manual...
  • Page 316 Tektronix service center or representative if message persists after normalization. UNCAL Indicates the 2715 is operating in an uncalibrated state. Occurs under the following conditions: H Sweep speed is too fast for a specified resolution BW, video filter, and span combination...
  • Page 317 WARNING: USING EMPTY ANT TABLE The table called for is empty. The function is still being performed but with values of zero for each increment of the table. ZERO SPAN ENTERED Instrument is now in zero span. C–15 2715 User Manual...
  • Page 318 Appendix C: System Messages C–16 2715 User Manual...
  • Page 319 Appendix D: Global Resets Settings on the 2715 can be reset in many ways. Some instrument settings are always reset, while others are never reset, and still others are reset during certain reset cycles only. This appendix includes a description of which settings are in each category, and when each category of settings is reset.
  • Page 320 POWER-UP DIAG AND REBOOT CYCLE Invoked with [UTIL] [5] [0] [9]. Reset Categories The 2715 has several distinct settings categories. Precious Settings Precious settings are not reset by any reset cycle. The settings in this class can only be changed by manually setting each to its desired value. The following are...
  • Page 321 H dBµV/M Target Waveform H Sweep/Trigger Menu Items H Video Sync Polarity H Video Line Triggering Mode (CONTINUOUS/KNOB/ENTERED) H Video Line Triggering Standard (NTSC/SECAM/PAL/OPEN) H Display Menu Items H Ensemble Averaging Destination Waveform H MIN HOLD Destination Waveform D–3 2715 User Manual...
  • Page 322 Normalization values for the last executed (passed) normalizations are always restored during the POWER DOWN/UP and the POWER-UP DIAG AND REBOOT cycles. The other cycles do not affect the normalization values. D–4 2715 User Manual...
  • Page 323 Simply insert an SMA-to-SMA cable between the LO IN connector on the rear of the 1405 (or J101 IN on the rear of the 2207) and J101 on the rear of the 2715. You can also superimpose frequency markers generated by the 1405 on the sweep produced by the 2715.
  • Page 324 The shell of this BNC input connector is at chassis ground. If you plan to use an external trigger (see SWP/TRIG in Spectrum Analyzer Menus), this is where the trigger signal is input to the 2715. The trigger signal must be positive-going and rise above 100 mV for at least 0.1 ms.
  • Page 325 5MHZ RBW (AUTO) CALIBRATOR Pin 1 — External Video Pin 1 enables you to introduce an external video signal to the 2715, in effect Input giving it limited oscilloscope capabilities. It is also used to introduce the frequency markers from the 1405 TV Sideband Analyzer (see the previous discussion of J101 on page E–1).
  • Page 326 3. Toggle DSPL menu item 7, DISPLAY SOURCE, to EXTERNAL. The 2715 reverts to the display mode in zero span (there is no need to sweep the signal past the resolution bandwidth filter since these circuits are bypassed). The top graticule line is 0 V.
  • Page 327 Pin 2 of the Accessory Connector contains the sweep gate. The sweep gate is a +5 V pulse whose leading edge is synchronous with the start of the 2715’s sweep. The trailing edge marks the end of sweep. See Figure E–2. The signal is usually used in conjunction with the video output (pin 5) to indicate when a new sweep is beginning.
  • Page 328 If the image is as desired, follow the next step (this can be especially important when you are trying to view time-varying analog spectra). H Turn on MAX HOLD in all the 2715 registers. Notice the analog trace is still displayed on the oscilloscope.
  • Page 329 If Option 03 (GPIB) is installed, J104 is a 24-pin IEEE Standard 488 GPIB connector. The pin-outs for the GPIB connector are shown in Figure E–3. Signal levels, handshaking, protocols, and other matters of importance to digital communications are detailed in the 2714 & 2715 Programmer Manual and the pertinent standards. NRFD...
  • Page 330 Figure E–4: RS-232-C Connector Pin Assignments The RS-232 connector (J104) on the 2715 is typically used to connect the 2715 to a PC that is running the Cable TV RF Measurements Software. The RS-232 connector on the PC interface card may be one of three types: H 9-pin female.

  • Page 331: Table E-1: 9-Pin Female To 9-Pin Female Null-Modem Cable

    Table E–2 and Figure E–6 show the wiring configuration for this type of cable. A cable with this configuration is available as an optional accessory. Refer to Appendix F: Accessories and Options for the part number. E–9 2715 User Manual...

  • Page 332: Table E-2: 9-Pin Female To 25-Pin Female Null-Modem Cable

    7 (GND) 6 (DSR) 20 (DTR) 7 (RTS) 5, 8 (CTS, DCD) 8 (see pin 1) 9 (not used) 9-Pin Female 25-Pin Female To 2715 To PC Figure E–6: 9-Pin Female to 25-Pin Female Null-Modem Cable E–10 2715 User Manual...

  • Page 333: Table E-3: 9-Pin Female To 25-Pin Male Extension Cable

    5 (GND) 7 (GND) 6 (DSR) 6 (DSR) 7 (RTS) 4 (RTS) 8 (CTS) 5 (CTS) 9 (not used) 9-Pin Female 25-Pin Male To 2715 To PC Modem Figure E–7: 9-Pin Female to 25-Pin Male Extension Cable E–11 2715 User Manual...
  • Page 334 Appendix E: External Input and Output E–12 2715 User Manual...

  • Page 335: Table F-1: Standard Accessories

    Appendix F: Accessories and Options Accessories The 2715 is shipped with the standard accessories listed in Table F–1. Optional accessories are listed in Table F–2. Also, optional AC mains power cords are available meeting various international standards (see Table F–3).

  • Page 336: Table F-3: Power Cord Identification

    016-0792-02 Transit Case Table F–3: Power Cord Identification Plug Configuration Normal Usage Option Number North America Standard 125 V Europe 230 V United Kingdom 230 V Australia 230 V North America 230 V Switzerland 230 V F–2 2715 User Manual...
  • Page 337 (Inverter/Battery Pack) Instruction Manual, and necessary mounting hardware. This option allows operation of the 2715 in locations where AC power is not available. The 2705 provides approximately one hour of operation when used with the 2704 Inverter and 2715. Operating time can be extended by using additional 2705 Battery Packs, or alternate 12 VDC sources.
  • Page 338 Option 34 Option 34 consists of a front panel mask and rack mounting cradle which adapts (Cradle Type Rackmount the 2715 to a standard 19 in (482.6 mm) rack. The adapter requires 7 in (177.8 mm) vertical rack space. Adapter) This option preserves the portability of the 2715.
  • Page 339 Glossary and Index...
  • Page 341 That frequency which corresponds to the center of a frequency span, expressed in hertz. Clear (Erase) Presets memory to a prescribed state, usually that denoting zero. Composite Second Order (CSO) Second order distortion products generated by the direct addition or subtraction of fundamental visual carrier frequencies. Glossary–1 2715 User Manual...
  • Page 342 The input frequency as indicated by the spectrum analyzer and expressed in hertz. Display Dynamic Range The maximum ratio of the levels of two nonharmonically related sinusoidal signals, each of which can be simultaneously measured on the screen to a specified accuracy. Glossary–2 2715 User Manual...
  • Page 343 The limits of an electrical signal or its parameters. For instance, the modulation envelope limits the amplitude of an AM carrier. Envelope Display The display produced on a spectrum analyzer when the resolution bandwidth is greater than the spacing of the individual frequency components. Glossary–3 2715 User Manual...
  • Page 344 The overall gain variation of a system as a function of frequency. Normally measured in dB p-p (sometimes called peak-to valley) or as dB (half the peak-to-peak value). Frequency Span (Dispersion) The magnitude of the frequency band displayed; expressed in hertz or hertz per division. Glossary–4 2715 User Manual...
  • Page 345 SAVE A trace or a trace recalled into the B display before the sweep is started. Input Impedance The impedance at the desired input terminal. Usually expressed in terms of VSWR, return loss, or other related terms for low impedance devices and resistance-capacitance parameters for high impedance devices. Glossary–5 2715 User Manual...
  • Page 346 Marks the current sweep position in a digital storage display as the display is being updated. Video Markers Marker signals applied to the external VID|MARKER input from a Tektronix 1405 Television Sideband Analyzer. The Video Markers mark frequencies of interest on the television signal.
  • Page 347 Peak Detection A detection scheme wherein the peak amplitude of a signal is measured and displayed. In spectrum analysis, 20 log (peak) is often displayed. Glossary–7 2715 User Manual...
  • Page 348 RBW determines how well the analyzer can resolve or separate two or more closely spaced signal components. Save A function which inhibits storage update, saving existing data in a section of multiple memory (for example, Save A). Glossary–8 2715 User Manual...
  • Page 349 The technique or process of determining the frequency distribution of a signal. Spectrum Analyzer A device for determining the frequency components of a signal. Spurious Response A response to a spectrum analyzer wherein the displayed frequency is not related to the input frequency. Glossary–9 2715 User Manual...
  • Page 350 A process wherein a saved waveform can be subtracted from a second, active waveform. Zero Pit (Response) An output indication which corresponds to zero input frequency. Zero Span An operating mode in which the frequency span is reduced to zero. Glossary–10 2715 User Manual...
  • Page 351 Arrow Keys, 2–8, 2–15 Desired-to-Undesired Measurement, 5–35 Channel Entry, 4–4 FREQUENCY RESPONSE, 5–43 CTR-MEAS/TRKG, 4–32 General (CATV) 2715 Mode, 5–4 Frequency Entry (NonCATV Mode), 4–7 HUM/LFD Measurement, 5–40 Frequency Entry (Normal Mode), 4–6 Initial Setup, 5–3 Reference Level Operation, 4–9 Input Power Limitations, 5–2...
  • Page 352 Exit From a Menu, 6–3 Equipment Setup for Field Strength Measurements, External Amplification/Attenuation, 6–6 6–11 External Source, Displaying, 6–40 Equivalent Decibel – Voltage Values, 6–12 Procedure, 6–12 Using, 6–10 Dedicated Controls, 2–8 Default Settings, restoring, 2–6 Index–2 2715 User Manual...
  • Page 353 File System, 6–75 Selecting a Channel Table, 5–6, 5–7 Antenna Table Files, 6–76 Signal Types, 5–4 CATV Measurement Results Files, 6–76 General (CATV) 2715 Mode, 5–4 Channel Table Files, 6–76 GPIB Curve Files, 6–76 Configuration, 6–69 Flatness Correction Data Files, 6–76 EOI/LF MODE, 6–70...
  • Page 354 Line Number, Test Signal, 5–63 SWP/TRG, 3–11 Line Trigger, TV, 6–85 USER DEF, 3–20 Listen Operation, 5–70 UTIL, 3–12 Listening to AM or FM Transmissions, 6–58 Menu-Entered Control Settings, 6–60 Mains Power, 2–3 Manually Scanning, 6–89 Marker Control, 4–26 Index–4 2715 User Manual...
  • Page 355 Normal Mode, Frequency Entry, 4–5 Receiving, 2–1 Normalization File, 6–76 REF LEVEL, 3–5 Normalization, Initial, 2–5 Arrow Keys, 3–5 Normalizing the 2715, 6–65 STEP, 3–5 Numeric Keys, 3–6 ZERO and MAX Keys, 3–5 NVRAM, If You Lose, 6–81 REF LVL STEP, 3–5, 4–10 Reference Level Operation Arrow Keys, 4–9...
  • Page 356 TV Video Field Triggering, 6–88 Service Request, Generating, 6–82 Set the Reference, 2–15 Setting Start and Stop Frequencies, 6–17 Setting the RF Attenuation, 6–4 Setting the Signal Threshold, 6–22 Settings and Displays, Save and Recall, 6–62 Settings Files, 6–76 Index–6 2715 User Manual...
  • Page 357 System Configuration, 6–67 Manual Adjustments, Aligning the Display, 6–78 Configuring the Communications Port, 6–67 Menu-Entered Control Settings, 6–60 Confirming Installed Options, 6–77 Normalizing the 2715, 6–65 File System, 6–75 Other User-Defined Settings, 6–63 Protecting Files, 6–77 Recall Last Power-Down Settings, 6–62 Protecting Stored Settings, 6–75...
  • Page 358 Index YIG Oscillator ZERO Key, 3–5 Changing Settling Delay Time, 6–79 Zero Span, 4–4 Minimum Acceptable Settling Time, 6–79 Settling Delay Time Default, 6–78 Index–8 2715 User Manual...

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