HP 8753E Service Manual

A3 Source and A11 Phase Lock Check
This procedure checks the source and part of the phase lock assembly. It opens
the phase-locked loop and exercises the source by varying the source output
frequency with the A11 pretune DAC.
Note
If the analyzer failed internal test 48, default pretune correction
constants were stored which may result in a constant offset of
several MHz. Regardless, continue with this procedure.
Note
Use a spectrum analyzer for problems above 100 MHz.
1. Connect the oscilloscope or spectrum analyzer as shown in Figure 7-l. (Set
the oscilloscope input impedance to 50 ohms)
. . . . . _ ..,., ,.,. . . ..,..
2.
,,.
mess (Preset, Lsyst~, ~~~~~~ ~~~~~~~~~; ~~~~~~~~~,
,.,.,...,.,.,.,,.,.,,j __;__~__~ .-,. i _ ._,,_ i _,__ i _ . . . . . . . . . . _____i _.. _ .,.; i . ..=.... _i . .._....... ./
,, _ ,,, ,.....,..... ..,,,,,, .,:...:.:.::.. i .._ __.................,.,.,.,.,.,.....i ._.; .,.. . . . .._.. __.
. . . . . . . . _ . . . . . . _
~~~~~~~ ~~~~~~ to activate *e SoUTce tune (SRC ME)
service mode.
3. Use the front panel knob or front panel keys to set the pretune frequency
to 300
kHz, 30 MHz, and 40 MHz. Verify the signal frequency on the
0sciIioscope.
Note
In SRC TUNE mode, the source output frequency changes in
1 to 2 MHz increments and should be 1 to 6 MHz above the
indicated output frequency.
4. Check for the frequencies indicated by Table 7-l.
I
‘Ikxble 7-1. Output Frequency in SEC Tune Mode
settins!
Observed Frequency
3ookHz
1.3 to 6.3 MHZ
3oMHz
31to36MHz
4oMHz
41to46lmz
5. The signal observed on an osciRoscope should be as solid as the signal in
Figure 7-4.
7-g SourceTroubleshooting

HP 8753E Specifications

General

Brand	HP
Model	8753E
Category	Measuring Instruments
Language	English