Call Lamp Control Relay (A-, B- and C- Models Only)

TM 11-5820-477-30

2-12. Call Lamp Control Relay (A-, B- and C- Models Only)

This task covers:

Removal

b. Installation

INITIAL SETUP

Tools

Tool Kit, Electronic Equipment TK-105/G

NOTE

Both local control unit and remote control unit are equipped with call lamps. Replacement

procedures are the same for both control units on all three models specified.

(1) Release clamp on each side of control unit and slide chassis out of case.

(2) Remove six panhead screws securing front panel (1) to chassis

(3) Pull out RINGER button (2) until it is disengaged from magneto connecting link, freeing front panel (1)

from chassis (3).

(4) Loosen call lamp control relay mounting screws (4) and lift call lamp control relay (5) from component

board A101 or A201 (6).

CAUTION

Do not use a soldering gun; damaging voltages can be induced in the components. Use

a pencil-type soldering iron with 25 watt maximum capacity. Both control units are

transistorized. If only at-operated iron is available, use an isolating transformer.

NOTE

When removing soldered leads, tag each lead as it is unsoldered from its terminal to

f a c i l i t a t e reconnection.

(5) Tag and unsolder wires connected to call lamp control relay (5) and remove relay.

b. Installation (figure 2-10)

CAUTION

Do not use a soldering gun; damaging voltages can be induced in the components. Use

a pencil-type soldering iron with 25 watt maximum capacity. Both control units are

transistorized. If only at-operated iron is available, use an isolating transformer.

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