Spectracom - Essential Ingenuity

CNT-91R-AF Calibration trigger level

Question

Why does the counter fail Trigger level and Sensitivity tests @ 10Hz?

Answer

Answer:
We are aware of a problem with the trigger level sensitivity test. There was an error in the Service Manual and Spectracom has revised the manual to change the test parameters.
 
 
Here is a portion of your USAF procedure that needs to be updated:
 
4.4 TRIGGER LEVELS CALIBRATION:

4.4.1 Press the TI auto set key twice to preset the TI.
4.4.2 Press the TI 6 (input A) key.
4.4.3 Press the TI 2 key, as required, to select DC, the 3 key, as required, to select 50 Ω, then the 5 key to select Man.
4.4.4 Connect the Function Generator to TI input A.
4.4.5 Set the Function Generator for 10 kHz sinewave at 900 mV p-p with +0.5 V offset.
4.4.6 Press the TI Trig key, enter +1 V, then press the exit key.
4.4.7 The TI trigger indicator must be off.
4.4.8 Press the TI Trig key, enter -1 V, then press the exit key.
4.4.9 The TI trigger indicator must be on.
4.4.10 Press the TI Trig key, enter 0.0 V, then press the exit key.
4.4.11 The TI trigger indicator must be blinking.
4.4.12 Set the Function Generator for minimum output.
4.4.13 Disconnect the Function Generator from TI input A and connect to input B.
4.4.14 Press the TI meas func key, the 1 (Freq) key twice, the 3 (B) key, then the 7 (input B) key.
4.4.15 Repeat steps 4.4.3 through 4.4.12 for TI input B.
4.4.16 Set all POWER switches to OFF or STBY. Disconnect and secure all equipment.

 
The new Trigger Level Indicator test changes the following parameters:
 
4.4.8 Press the TI Trig key, enter 0.0 V, then press the exit key.
 
4.4.10 Press the TI Trig key, enter 0.5 V, then press the exit key.
 

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