5-9.
FM ACCURACY AND FM OVERMOD ADJUSTMENT (Cont’d)
7. On the OUT, press [CW] [4]
[.]
[5] [GHz].Press [FM]
to turn the
FM on and use the UP ARROW
step key to select 10 MHz/V FM sensitivity.
8. Set the function generator for a 1.5 MHz sine wave and adjust the amplitude for a 0.707 Vms
reading on the OVM.
9. Connect the oscilloscope’s Channel A input to A49TP1. Set the oscilloscope for 0.01 V/div, ac
coupled, and 0.5 us/div. The oscilloscope display should look similar to Figure 5-27.
10. Adjust A49R3 until the OVERMOD annunciator on the OUT’s front panel turns on, then adjust
A49R3 until the OVERMOD annunciator just turns oft.
11. Disconnect all of the test equipment from the OUT. Reinstall the cover onto the A49 Phase
Detector assembly and reinstall the YO Loop into the OUT.
nS’~iv
C.
~
~
4-4-Il.
A
l~\
A
A
A
(~
A~
~ U U
~I Y ~
V
K~ \ ~ I \~ \
C
C
~
~
~
I~
Figure 5-27.
Typical Waveform at A49TPI
HP 8340B/41B
Adjustments
5-55/5-56
‘N
<0
