Frequency Dial Restringing; Ac Dial Restringing - HP Q METER 4342A Operating And Service Manual

Section V
Paragraphs 5-31 to 5-36
5-31. DIAL RE-STRINGING INSTRUCTIONS.
5-32. This paragraph explains how to re-
string and set the dial drive strings which
move
FREQUENCY, L/C, and C dials which
rotate the internal variable capacitors.
To
maintain dial scale accuracy and smooth dial
operation, the dial string must be correctly
wound on and attached to the drum scale
pulley and dial or capacitor pulley and its
tension set properly. If a dial string is
off or loose, repair the string in accord
with the following instructions which outline
the procedures for correctly interlocking
dial and capacitor.
5-33. For access to internal dial interlock-
ing mechanism, remove control panel, top,
bottom, and side covers, and side frames as
follows:
a.
b.
C.
d.
e.
f.
Turn instrument off and remove power
cord.
Unscrew the four retaining screws and
remove top cover. Remove bottom cover
with like procedure.
Remove the four retaining screws lo-
cated at the left and right (top and
bottom) sides of the control panel.
Lift control panel front edge up and
remove the panel.
Remove both side panels by removing
the four screws on each side.
Remove both side-casting-frames by
removing the eight screws on each side.
Model
4342A
5-34. FREQUENCY DIAL.
The parts required for stringing frequecy
dial are:
1)
String I:
f1P Part No. 04342-8541
2) String II:
HP Part No. 04342-8542
3)
Belt: HP Part No. 04342-1051
4)
Screws (2):
HP Part No. 0520-0127
Frequency dial re-stringing procedure is
illustrated in Figure 5-8.
5-35.
L/C DIAL.
To re-string tuning capacitor dial, the
following parts are required:
1)
String I: HP Part No. 04342-8541
2) String II: HP Part No. 04342-8544
3) Belt: HP Part No. 04342-1052
4)
Screws (2): f1P Part No. 0520-0127
L/C dial re-stringing procedure is illustratd
in Figure 5-9.
5-36. AC DIAL.
To re-string AC dial, the following parts are
required:
1)
String I: HP Part No. 04342-8541
21
String II: flP Part No. 04342-8543
3)
Belt:
HP Part No. 04342-1053
4)
Screws (2): HP Part No. 0520-0127
AC dial re-stringing procedure is illustrated
in Figure S-10.
5-14