TM 11-5805-356-34-1
(6) Solder the junctions of the foil and copper
CAUTION
wire by applying the soldering iron to the copper
Never bring the soldering iron into direct
wire.
contact with the transistor body or any
heat conductor which is in direct contact
with the transistor body. The excessive
The test equipment and materials required to per-
temperature will destroy the transistor.
form the following procedure are listed in section II.
(2) When soldering transistor leads, solder
a. Provide 600-ohm load at line terminals.
quickly; use a heat sink (such as a long-nose pliers)
b. Operate the switches as follows:
between the soldered joint and the transistor.
Position
Switch
(3) Use approximately the same length and
ON-OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. OFF
dress for transistor leads as used originally.
MODE ONE-MODE TWO . . . . . . . ..MODE ONE
b. Part Replacement.
4W-2W-TEL... . . . . . . . . . . . . . . . . . . . . . . . . . . ..4W
(1) Remove the part by cutting the leads approx-
NORM-REC-SEND . . . . . . . . . . . . . . . . . ..SEND
imately 1/16 inch from the printed circuit board.
115V AC-230V AC 26V DC. Position that corresponds to in-
put power source.
CAUTION
Connect the AN/USM-459 to 4WS-TEL line
c.
Never bring the soldering iron into direct
terminals E3 and E4.
contact with the printed circuit. Excessive
d. Operate the TH-22/TG ON-OFF switch to ON.
heat will damage the printed circuit.
e. Be sure the frequency at the line terminal is
(2) Remove the leads from the printed circuit by
1,317.5 Hz 3, which is the mark frequency. If the
applying the iron to the lead until the solder melts at
correct frequency is not indicated, adjust trimmer
the junction.
capacitor A1C9 (fig. 3-3) to obtain the correct fre-
(3) Remove the excess solder from junction on
quency indication. If unable to bring frequency into
the printed circuit board with a small drill. Always
range, send TH-22/TG to higher category of mainte-
drill from the printed circuit side of the board to
nance.
prevent loosening of the printed circuit foil.
f. Insert an open plug into the SEND jack, provid-
(4) Use approximately the same length and
ing space input.
dress for part leads as was used originally.
g. Be sure the frequency at the line terminal is
(5) Solder the component leads to the printed
1,232.5 Hz 3, which is the space frequency. If the
circuit by applying the soldering iron to the compon-
correct frequency is not obtained, adjust trimmer
ent lead and removing the iron as soon as the solder
capacitor A1C5 (fig. 3-3) to obtain the correct fre-
flows into the junction.
quency. If unable to bring frequency into range, send
c. Pc Board Repair. Follow the procedures given
TH-22/TG to higher category of maintenance.
below if the foil of the pc board is loose or broken.
h. Remove the open plug, and be sure the VF-20
(1) Remove the loose or broken foil by cutting it
switch is at VF.
as close to the board as possible.
i. Operate the RING switch, and be sure the fre-
(2) Cut a piece of tinned 20-gage copper wire 1/2
quency, while the switch is held operated, is 1,232.5
inch longer than the span of the removed section of
foil.
(3) Bend each end of the copper wire 1/4 inch from
j. Operate the BREAK IN switch, and be sure the
the ends until its shape resembles a stapled.
break-in frequency of 1,180 Hz 3 is indicated. If the
(4) Drill a small hole in the board at each end of
correct frequency is not indicated, adjust trimmer
the span where the loose or broken foil was removed.
capacitor A1C13 (fig. 3-3) to obtain the correct fre-
If the foil at each end of the span is 1/4 inch or more in
quency. This action completes the send circuit ad-
width, drill the hole directly into the foil.
justment. If unable to bring frequency into range,
(5) Insert the ends of the copper wire from the
send TH-22/TG to higher category of maintenance.
component side of the board and bend the ends
across the foil.
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