Fluke 6080A Service Manual page 141

Table 6C-1. Sub-Synthesizer PCA Test Points
Front panel frequency set to 804.001499 MHz
Typical:
Range: Total Sub-Synthesizer frequency range (160-320 MHz)
Front panel from 800.000000 to 807.999999 MHz
TEST SIGNAL
POINT TYPE
TP2 ground
TP3 TTL 20MHz, 12.5 ns (AH)
TP4 TTL 20MHz, 12.5 ns (AH)
10-19.98 MHz
TP5 TTL
TP6 DC 0-10.23V
TP21 TTL 1 MHz, 50 ns (AL)
TP22 TTL 1 MHz square wave
TP23 ground
TP24 TTL 1 MHz, 10 ns (AH)
TP25
TTL 1 MHz, 150 ns (AH)
TP26 ground
TP27 DC 2-24V
TP30 TTL 10-19.98 kHz
TP31 TTL 1-1.998 MHz
ground
TP32
TP33
TTL 9-19 MHz
TP34 TTL 0-1 MHz
TP35 DC 0-10.23V
TP36 input
TP37 audio 10-19.98 kHz
450 mV p-p
TP38 audio 10-19.98 kHz
450 mV p-p
TP39 DC 0-10.23V
TP40 DC 2-24V
TP41 2-24V
DC
RANGE TYPICAL
Constant
Constant
19.98 MHz
2.2V
1 MHz
1 MHz
1 MHz
1 MHz
8.6V
19.98kHz
1.998 MHz
15MHz
10kHz
50 ns (AL)
1.6V
19.98kHz
19.98kHz
varies
8.6V
8.6V
TROUBLESHOOTING AND REPAIR
FUNCTION
2-phase clock generator
2-phase clock generator
Low order digit gate array output
Coarse Loop VCO steering DAC output
N-Divider output
Reference divider output
Phase detector down output
Phase detector up output high
~2.8V, low ~-0.5V
Sub-Synthesizer VCO control voltage
Low order digits signal
Intermediate low order digits signal
(divide-by-10)
Triple modulus pre-scaler output
Modulus select signal
Sub-Synthesizer loop gain
compensation DAC (KN) output
For calibration of low-pass filter
Active quadrature generator output
Active quadrature generator output
Reference oscillator voltage
DAC output
Loop amplifier output
Low-pass filter input TP40-TP41
normally connected together, except
when troubleshooting
FREQUENCY SYNTHESIS
6C-11