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AR 681 Operating And Service Manual

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Operating and
Service Manual
681
Model
10029616
Part Number
Serial Number
EXPORT CONTROLLED DATA.
These commodities, technology or software are controlled for export in accordance with the U.S. Export
Administration Regulations. Diversion contrary to U.S. law is prohibited.
160 School House Road, Souderton, PA 18964 • 215-723-8181 • Fax 215-723-5688 • www.arworld.us

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  • Page 1 Operating and Service Manual Model 10029616 Part Number Serial Number EXPORT CONTROLLED DATA. These commodities, technology or software are controlled for export in accordance with the U.S. Export Administration Regulations. Diversion contrary to U.S. law is prohibited. 160 School House Road, Souderton, PA 18964 • 215-723-8181 • Fax 215-723-5688 • www.arworld.us...
  • Page 2 WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...
  • Page 3 LVD Directive 2006/96/EC Reference standards: EN 61010-1:2010 Safety requirements for electrical equipment for measurement, control, and laboratory use. Supporting documentation is held by AR RF/Microwave Instrumentation’s quality department in Pennsylvania, United States. Place of issue: AR RF/Microwave Instrumentation 160 School House Road...
  • Page 4 WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...
  • Page 5 Instructions for European EMC Conformity WARNING It is the responsibility of the user of this equipment to provide electromagnetic shielding, filtering and isolation which is necessary for EMC compliance to Directive 89/336/EEC. The equipment must therefor be operated in a shielded area which provides a sufficient level of attenuation to meet the radiated emissions and immunity specifications.
  • Page 6 WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...
  • Page 7 INSTRUCTIONS FOR SAFE OPERATION BEFORE APPLYING POWER SAFETY SYMBOLS This symbol is marked on the equipment Review this manual and become familiar with all safety when it is necessary for the user to refer to markings and instructions. the manual for important safety information. Verify that the equipment line voltage selection is compatible with the main power source.
  • Page 8 WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...

  • Page 9: Table Of Contents

    TABLE OF CONTENTS TABLE OF CONTENTS ....................iii GENERAL INFORMATION ................1 General Description ....................1 Specifications ......................1 Power Supplies ....................... 1 Protection Circuits ....................2 Installation ......................2 1.5.1 Location ........................2 1.5.2 Power ........................2 OPERATING INSTRUCTIONS ................ 5 General ........................
  • Page 10 Model 681 3.2.8 A19 Detector Assembly ..................25 Power Supplies (PS1 and PS2) ................25 3.3.1 A20 Regulator Board (Schematic #10027610) ............ 25 Control System ..................... 26 3.4.1 A11 Control/Fault Board (Schematic #10021920) ..........26 3.4.2 A14 Interface Board (Schematic #10020073) ............. 26 3.4.3...

  • Page 11: General Information

    The Model 681 can be operated locally by using the unit’s front panel controls, or remotely by using the unit’s IEEE-488, RS-232 interface, USB, or Ethernet interface.

  • Page 12: Protection Circuits

    Select an operating location that will permit air to circulate freely around the amplifier’s cabinet. T he Model 681 utilizes air cooling and should be located where the normal flow of air into or exiting from the unit will not be restricted, diverted, or re-circulated through the unit itself; in particular, the flow of warm air exiting the rear of the amplifier should not be impeded.
  • Page 13 The low level of spurious signals and linearity of the Model 681 make it ideal for use as a driver amplifier in testing wireless and communication components and subsystems.
  • Page 14 SPECIFICATIONS, 681 RATED POWER OUTPUT ..........200 watts typical 190 watts minimum, 0.7-3.0 GHz; 180 watts minimum, 3.0-4.2 GHz 200 watts minimum, 728–960 MHz 1475–1559 MHz 1805–1990 MHz 2010–2170 MHz 2570–2690 MHz INPUT FOR RATED OUTPUT .......... 1.0 milliwatt maximum POWER OUTPUT @ 3dB COMPRESSSION Nominal ..............

  • Page 15: Operating Instructions

    The 681 Amplifier is protected from input overdrive by an automatic level control circuit which will limit the maximum RF level to the first gain stage (U2) of the RF Amplifier to approximately 0 dB m. The 681 RF power transistors are protected from over temperature by sensing the chassis temperature near the RF output transistors.

  • Page 16: Power Switch

    Model 681 2.2.2 POWER Switch The momentary POWER switch turns the main power to the amplifier on and off. The status of the green light-emitting diode (LED) in the switch indicates whether the amplifier’s power is on or off. The main power supply fans are active when power is on.

  • Page 17: Main Power

    Model 681 2.2.3 Main Power The Main Power circuit breaker is located on the rear panel of the amplifier. Figure 2-2. Rear Panel Features 2.2.4 RF ON/OFF The RF ON/OFF button toggles the amplifier from a Standby to an Operate mode. The status of the function is indicated on t he display as RF ON or RF OFF.

  • Page 18: Digital Control Panel (Dcp) Operations

    Model 681 DIGITAL CONTROL PANEL (DCP) OPERATIONS The operations described in this section assume that the user is performing these operations from the amplifier’s front panel with the Keylock Switch in the LOCAL position. Computer access to command and status functions is also available when the Keylock Switch is set to REMOTE. R efer to section 2.5.5 for information on remote operation.

  • Page 19: Lcd Soft Key Screens

    Model 681 Figure 2-3. LCD Soft-Key Screens Rev A WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...

  • Page 20: Rf Gain Control

    IEEE-488, USB, and RS-232 Interfaces The Model 681’s remote interfaces allow remote control, via a computer, of all amplifier functions (except for the Keylock Switch position) that can be controlled from the front panel. When the amplifier is in the Remote mode (as determined by the position of the Keylock Switch), a special Remote display is shown (see Figure 2-3).

  • Page 21: Safety Interlock Connector

    Model 681 2.4.4 Safety Interlock Connector The safety interlock connector interface provides for external safety switch interlocks that will prevent the amplifier from entering or being placed in the Operate mode unless an external connection is made. A connection between Pins 1 and 8 must be completed to operate the amplifier.

  • Page 22: Rs-232 Communications

    Model 681 When sending commands to the unit via the GPIB interface, terminate the command with a <LF>, an EOI, or both. The system ignores characters following the termination. 2.6.1.1 Setting the IEEE-488 (GPIB) Address The IEEE-488 device address can be set to any number between 1 and 30. This selection is made by setting Switches 1 to 5 of the rear panel DIP switch to the binary equivalent of the number.

  • Page 23: Fiber-Optic Communications

    The connector type for this port is ST. This port can be used with either an AR IF7000 RS-232 to Fiber-Optic Interface or an AR IF7001 USB to Fiber-Optic Interface. Note that these devices use SMA connectors so a fiber-optic cable is needed with ST connectors on one end and SMA connectors on the other.

  • Page 24: Usb Communications

    Automation Explorer or LabView. I f a user wishes to write code in a different programming language, a custom driver can be requested from AR. It should be noted that the USBTMC driver provided by National Instruments is a VISA driver which can be used with other programming languages besides LabView. For more information on this please consult the National Instruments Website found at www.ni.com.

  • Page 25: Remote Commands

    Model 681 2.6.6 Remote Commands All commands are available to the user for remote operation of the amplifier. • If a command is unrecognized it is echoed back out the port it came in on. • All commands and queries are terminated with a <LF>.
  • Page 26 Model 681 2.6.6.1 Power On/Off This command controls the power on/off state of the amplifier. Syntax: POWER:x Parameters: State(x): OFF = power off ON = power on Response Format: None (No query for this command) Example: To turn the power on, send the following command: POWER:ON<LF>...
  • Page 27 Model 681 2.6.6.4 Level Adjust This command sets the RF gain of the amplifier. Syntax: LEVEL:xy Parameters: Parameter(x): GAIN = RF Gain Value(y): For RF Gain: 0 = Minimum 100 = Maximum Response Format: None (No query for this command)
  • Page 28 Model 681 2.6.6.6 IO Board Firmware Revision Query to get the firmware revision of the IO Board. Syntax: *IOB? Parameters: None Query only (always requires a ? character) Response Format: INTERFACE_BOARD_SW_REVx<LF> Where: x = firmware revision Example: To get the firmware rev. of the IO Board, send the following command: *IOB?<LF>...
  • Page 29 Model 681 BIT STATE BIT DESCRIPTION NOTES: POSITION PULSE STATUS PULSE BLANK SELECTION From PROGRAM or INHIBITED STATUS REPORT CONFIG.STRING BLANK DISABLED ENABLED REMOTE CONTROL (read only) DISABLED ENABLED Response to key-switch position POWER STATUS POWER ON STANDBY STATUS STANDBY...
  • Page 30 Model 681 2.6.6.9 Reverse Power Query to get the reverse power. Syntax: RPOW? Parameters: None Response Format: RPOW=x Where: x = 0 to 99999 Values are corrected and linearized. T hey can be up to five digits in length. Leading zeros are read as spaces.
  • Page 31 Model 681 Description No Fault (unused) Interlock Thermal Driver RS-485 Error DC OK Amp A3 Amp A5 Amp A6 Amp A9 Amp A10 Amp A11 Amp A12 Amp A13 Amp A14 Amp A15 Amp A16 Thermal Final Left Thermal Final Right...
  • Page 32 Model 681 Rev A WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...

  • Page 33: Theory Of Operation

    3. THEORY OF OPERATION INTRODUCTION The Model 681 RF amplifier consists of a 0.8–4.2 GHz RF amplifier assembly. The RF amplifier assembly consists of a P re-Amplifier (Pre-Amp), a Driver Amplifier (Driver Amp), a Quadrature-Coupled Amplifier (Quad Amp) used as a d river, a two-way splitter, (2) quad amplifiers used as drivers, (2) four-way splitters, (8) quad amplifiers and an 8-way combiner.

  • Page 34: A2 Driver Amp (Schematic 10025421)

    Model 681 3.2.2 A2 Driver Amp (Schematic 10025421) The Driver Amp is assembled on a Teflon®/glass printed wiring board (PWB). It has three (3) GaAs FET gain stages. Each stage is input and output DC isolated by coupling capacitors. Resistive feedback is used from the drain to the gate of the GaAs FET to decrease the low-frequency gain.

  • Page 35: A17 Eight-Way Combiner

    Model 681 3.2.6 A17 Eight-Way Combiner A17 is an Eight-Way radial combiner with impedance-matching. W hen the outputs of the eight quad amplifiers are fed to the eight-way combiner, the combined output will be approximately 9dB above the output of a single quad amplifier.

  • Page 36: Control System

    Model 681 U3 is a negative regulator (-5 VDC). This regulator supplies voltage for the gate voltages of the A2 Driver Amplifier. CONTROL SYSTEM 3.4.1 A11 Control/Fault Board (Schematic #10021920) The A11 Control/Fault board consists of two 16-bit microcontrollers and about nine other ICs that monitor and indicate the status of the amplifier.

  • Page 37: Maintenance

    4. MAINTENANCE GENERAL MAINTENANCE INFORMATION The Model 681 requires very little maintenance since it is a relatively simple instrument. It is built with etched circuit wiring and solid state devices that will ensure long, trouble free life. However, should trouble occur special care must be taken in servicing to avoid damage to the devices or the etched circuit board.

  • Page 38: Troubleshooting

    GaN HEMTs and other ESD-sensitive devices. Troubleshooting the Model 681 in a logical manner can speed the solution to a problem. The settings of potentiometers (pots), capacitors (caps), or other variables should not be disturbed until other problems have been eliminated.

  • Page 39: General - Reading Faults

    The digital control panel of the 681 indicates the output power from the 681 and the power reflected back to it. If the reflected power is very high, with respect to the forward power, this could indicate that the output coax cable is defective or that the load being driven has a high VSWR.

  • Page 40: Interlock Fault (Schematic Diagram No. 10028672)

    RF energy when these doors are opened. NOTE: The Model 681 is shipped with a mating connector, which has a jumper between Pins 1 and 8, installed in the rear panel interlock connector. The unit will not operate unless the interlock circuit is closed.

  • Page 41: Alc Fault

    Low or No Power Output (DC Tests) (Schematic Diagram No. 10028672) All indicators on the Model 681 are normal, the front panel display reads RF On, and the cooling fans are operating. 1. Check the position of the RF Gain control—is it set to maximum gain? 2.

  • Page 42: Typical Response @ 0Dbm Input

    1. The Model 681’s typical gain response at 0 dBm input and -20 dBm input is shown in Figures 4-1 and 4- 2. The actual gain may vary considerably from that shown in Figure 4-1 but should be ≥ 52.5 dBm.

  • Page 43: Typical Response: Input A4 Front Panel Rf Output

    Model 681 2. Remove the coaxial cable from the output of the A3 Quad Amp to the input of the A4 Two-Way Splitter. The typical response from the input of the A4 Two-Way Splitter to the RF Output connector on the unit’s front panel is shown in Figure 4-3.

  • Page 44: Typical Two-Way Splitter Insertion Loss

    Model 681 4. If the gain is 5dB or more below the typical response, do the following: • Disconnect the coaxial cable from the input of the A5 Quad Amp, and note the results. • Reconnect the coaxial cable from the input of A5 and disconnect the coaxial cable from the input of the A6 Quad Amp;...

  • Page 45: Typical Eight-Way Combiner Insertion Loss

    Model 681 7. A typical Eight-Way Combiner Insertion Loss and Combined Port Return Loss is shown in Figure 4-7. The unused port must be terminated when checking the Insertion Loss. NOTE: The Return Loss of the Eight-Way Combiner’s combined output port is typically better than 17dB (see Figure 4-8).

  • Page 46: Typical A2 Driver Amplifier Response

    Model 681 9. The typical response for the A2 Driver amplifier is shown in Figure 4-10. Figure 4-10. Typical A2 Driver Amplifier Response 10. The typical response for the A1 Preamplifier (at maximum gain setting) is shown in Figure 4-11.
  • Page 47 Meters, Directional Couplers, Field Monitoring Equipment, Conducted Immunity Generators, Signal Generators and Tripods will be free from defects in material and workmanship for a period of three (3) years from date of shipment shown on AR RF/Microwave Instrumentation invoice. Traveling Wave Tubes in the 200T2G8A, 250T1G3 and 250T8G18 will be free from defects in material and workmanship for a period of two (2) years from date of shipment.
  • Page 48 WARNING: EXPORT-CONTROLLED WARNING: EXPORT-CONTROLLED...

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