HP 8568B, Performance Tests And Adjustments Manual, Page: 252 / 313

22. Comb Generator Adjustments
a typical comb tooth display. See Figure 3-83 for location of
adjustments.
14. The majority of the comb teeth should be above the -30
Display Line. No comb teeth should exceed -22 and no
comb teeth should be less than -36
15. If unable to adjust comb teeth as described in previous steps,
proceed with the next step. If comb teeth are adjusted properly,
do not perform the adjustments in the following steps. Skip to
step 21.
16. Adjust COMB PEAK for maximum amplitude of
comb teeth. See Figure 3-83 for location of adjustment.
17. If the highest-frequency comb tooth is too low
remove screws from cover of Comb Generator and lift
cover from housing, being careful not to break wire connections
to internal circuit. It will be necessary to hold cover away from
housing while performing the following adjustment.
18. Adjust HF PEAK for maximum amplitude of the
highest-frequency comb tooth displayed ( comb tooth to far right
of CRT). See Figure 3-84 for location of adjustment.
19. Replace cover on and install screws.
20. Go back to step 12 and proceed with adjustments.
21. Remove cable from between and 1 and
reconnect instrument cables to connectors from which they were
removed.
3-138 Adjustments