15-6
Diagnostics Theory
RF_DIAGS
RF Generator Step Loop
This test checks the A26 Step Loop A assembly.
RF Generator Loop 1 MHz Reference Detector
This test checks for the presence of a reference.
RF Generator Loop Lock Detector State
The lock detector is checked at several frequencies.
RF Generator Loop Output Detector
The level detector is checked at several frequencies.
Sum Loop
This test checks the A25 Sum Loop assembly.
RF Generator Sum Loop Lock Detector State
This test checks the lock detector at several frequencies.
RF Generator Sum Loop VCO Tuning Level
This test checks the VCO tune voltage at several frequencies.
Output Section
This test checks the A13 Output assembly.
Power Supplies and Amplifier Bias
The+8 Vdc supply generated by the A13 Output assembly is measured by the voltmeter at
the OUT_POS_8V output. The -6 Vdc supply generated by the A13 Output assembly is
measured by the voltmeter at the OUT_NEG_6V output. The bias voltage on the output
amplifier is measured by the voltmeter at the OUT_AMP_BIAS output.
Carrier Level DAC
Thecarrier level DAC is checked first by turning on each bit one at a time and then with all
thebits on, measuring with the voltmeter at the OUT_LEVEL_REF output. The limits are
based on the value of the -6 Vdc measurement.
Filter Tune DAC
The filter tune DAC is checked the same way the carrier level DAC is checked at the
OUT_TUNE_FILTER output.