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I.
The frequency indicated at the top of the screen is now that of the desired incoming signal. It can also
be monitored for call signs, etc.
NOTE
The spectrum analyzer is functional but uncalibrated for level measurements in
Power Monitor mode for tr.ansmitter testing with the built-in 125 watt 50 ohm load.
(Observe "RF LOAD OVERTEMP" warning for high power levels or extended
periods of use.}
R-2001
CENTER FRED
, .1.
,I
II>
4~~.
'ZSO IIIIZ
1--
CENTER
FREQUENCY
8521-25
Figure 4-6.
Spectrum Test Setup and CRT Display
4-12.
MONITOR.
The analyzer is capable of monitoring the same frequencies that it generates (para 4-9}.
Select Gen/Mon Mtr in the DISPLAY column and the modulation type in the FUNCTION column. Set the
FUNCTION switch to the Monitor position for small signal samples or off the air monitoring. For high power
signal monitoring (0.2w to 125w), set the FUNCTION switch to Pwr Mon.
CAUTION
To prevent undue stress on the protected circuits it is advisable to always switch the
system to the power monitor mode before applying power in excess of 200 mw.
Additional protection is also obtained by making it a practice not to leave the step
attenuator in the 0 dB position.
NOTE
High-powered equipment in the 1-30 MHz range, which has unusually fast carrier
rise times, may damage the system analyzer with repeated activation of the protect
circuit. Ensure the FUNCTION switch is in the Pwr Mon position (this enables the
protect circuit} before RF power is applied to the equipment.
In the monitor mode the CRT displays the type of signal being monitored, the selected frequency, power, error
of the received frequency, and the modulation level.
4-16
d.
Select AM function.
e.
Using a tuning tool, adjust time base frequency calibration control (on l:ft side of housing) until CRT
frequency error display indicates less than 5Hz error. Frequency settabil1ty to 0.5 part per million can
thus be achieved using a 10 MHz frequency standard station.
NOTE
The time base output is also available on the rear panel for external measurement or
laboratory calibration to better than the 0.5 ppm achievable with the above method.
NOTE
An external time base input is also provided on the rear panel.
R-2001A
RF IN/OUT
ANALOG
INDICATOR
OF CARRIER -
ERROR
- ·
-----
-1
s'
I
ANALOG INDICATOR
OF% AM
5.4
8521·22
-CARRIER
ERROR
-
POS% AM
Figure 4-4.
System Analyzer Time Base Calibrate Test Setup and CRT Display
4-8.
GENERATOR OPERATION.
The system generates RF frequencies for FM, AM, CW, SSB, and DSBSC
types of transmission covering a range of 10kHz to 1000 MHz. To generate a signal the FUNCTION switch is
placed in the Gen. position.
NOTE
An RF protection circuit to protect against damage due to inadvertent application of
RF power to the unit, when in a generate or sensitive monitor mode, is functional
over the full monitor frequency range of the equipment (2 to 1000 MHz).
The type of signal is selected using the FUNCTION select LED indicator column. The unit can deliver an output
of up to 1 volt into 50 Ohms. When in the AM generate mode the variable control (located in the RF SECTION
on the front panel) should not be set above the AM limit mark. Exceeding this may cause distortion in the
output.
4-13
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