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Model 654A
Section V
d. To mount a new component, shape the leads and
insert them in the holes. Clip a heat sink on the
component, heat with the soldering iron, and add
solder as necessary to obtain a good electrical
connection.
5-101. SERVICING ROTARY SWITCHES.
5-102. The Model 654A contains two rotary type switches:
FREQUENCY RANGE and the ATTENUATOR. When
working on these switches, observe the following rules:
a. Use a low heat (25 to 50 watts) soldering iron
with a small tip.
b. When replacing components, attempt to dress
them as nearly to their original alignment as
possible.
c. Clean excessive flux from the connection and
adjoining area.
d. After cleaning the switch, apply a light coat of
lubriplate to the switch detent balls. DO NOT
apply lubricant to switch contacts or allow lubri-
cant to contaminate components.
e. To eliminate excessive contact wear and oxidation,
the contacts may be lubricated with Electrolube
2G, -hp- Part No. 5060-6086. Only a very small
amount of lubricant is necessary. Note: Electro-
lube 2G will change to a reddish brown color with
time; however, the lubricating properties are not
affected. A more detailed description on how to
apply Electrolube 2G is available at no cost from
your local Sales and Service Office. Ask for Service
Note M45 B.
5-103. SERVICING TUNER ASSEMBLY.
5-104. When replacing the tuning capacitor, Cl, make
certain that the tuner coupler and the frequency dial shaft
are aligned to prevent binding of the FREQUENCY Dial or
VERNIER control. If necessary, remove the frequency dial
knob, frequency dial, and loosen the tuner drive assembly
(casting and spur gears) retaining screws; then align tuner
coupler and frequency dial shaft. Tighten retaining screws
after tuner coupler and dial shaft are aligned.
NOTE
For correct alignment, refer to Frequency
Dial Calibration, Paragraph 5-52.
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BOTTOM
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653A-8-3635
653 - B- 3636
Figure 5-17. Atignement Access Covers for Models 651B, 2A, 3A, 4A
5-25
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