Markerandsampleradjustments - HP 83522A Service Notes

Adjustments
ADJUSTMENTS
Model 83522A
5-26. F M DRIVER (Cont'd)
9. Manually sweep function generator frequency from DC to 10 MHz. Adjust A5C14
"LO" and A5R75 "HI" controls several times (Figure 5-30) to obtain the most constant
overall response from DC to 10 MHz.
10. Check that +3 dB flatness specification is met between DC and 2 MHz as follows.
Manually sweep the function generator frequency between DC and 2 MHz. On the
oscilloscope, note maximum and minimum response points (Figure 5-3 1). Maximum
point (+3dB) can be up to 5.6 divisions, and minimum point (-3 dB) can be down to
2.8 divisions.
11. If the flatness specification in step 10 above is not met, repeat step 8 and 9 above and
make compromise adjustments in the DC to 2 MHz range to meet flatness
requirements.
MINIMUM
(-3
dB)
MAXIMUM
(+3 dB)
Figure 5-31. FM Flatness Tolerance, DC to 2 MHz
5-27. MARKERANDSAMPLERADJUSTMENTS
REFERENCE:
Performance Test: Paragraph 4-1 6
Service Sheets: A7 and A8.
DESCRIPTION:
Internal crystal markers are generated by mixing derivatives of a 50 MHz crystal oscillator
with the sweep. Proper marker functioning requires adjustment of the crystal oscillator, the
internal mixer, and IF gain for each marker frequency.