TB 9-6625-1932-35
b. Adjustments (Hewlett-Packard, Models 478A and 8478B only)
CAUTION
Use extreme care when making A adjustments (fig. 7) in the cw
direction. Over adjustment will damage TI.
Figure 7. Hewlett-Packard, Models 478A and 8478B only - adjustment locations.
(1) Set power meter No. 1 power switch to OFF.
(2) Adjust power meter No. 1 COARSE ZERO control to midrange (five turns from
fully ccw) and set RANGE switch to COARSE ZERO.
(3) Remove three screws on thermistor mount.
(4) Slide cover to expose thermistor and circuit card. Set power meter No. 1 power
switch to ON.
(5) Adjust A adjustments (fig. 7) ccw to adjust down scale and cw to adjust up scale.
NOTE
Both A adjustments (fig. 7) should be made as equal as
possible.
9. Final Procedure
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.
16