RAD/SPKR Position

TM 11-5820-477-30

(1) Receive operation. The battery voltage is connected to pin D of P201 and contact 10 of switch S202B.

Switch S202B (contacts 10 and 8) and relay K201 (terminals 4 and 3) connect the battery voltage to pin F of

P201 .

(2) Transmit operation. The battery voltage is connected through switch S202B (contacts 10 and 8) to

terminal 1 of relay K201. When the handset push-to-talk switch is pressed, a ground is applied through resistor

R225 to terminal 5 of relay K201 and causes the relay to energize. Relay K201 (terminals 4 and 2) connects the

voltage to terminal 4 of component board A201 to provide operating voltage for oscillator Q204. From terminals 4

and 2 of relay K201, voltage is applied through switch S202B (contacts 2 and 12) to terminal 3 of component

board A201 to provide operating voltage for audio amplifier Q205 and pin J of P201 to provide operating voltage to

the preamplifier (Q201 and Q202).

b. RAD/SPKR Position. With the TEL-RAD-RAD/SPKR switch in the RAD/SPKR position, battery voltage is

applied to audio driver Q203 and power amplifiers Q206 and Q207 during receive operation, and to the

preamplifier (C1201, Q202) and the tone generator (Q204, C1205) during transmit operation.

(1) Receive operation. The battery voltage is connected to pin D of P201 to provide operating voltage to

audio driver Q203. Battery voltage is connected to pin F of P201 through switch S202B (contacts 10 and 9) and

relay K201 (terminals 4 and 3) to provide operating voltage to audio driver Q203. Battery voltage for power

amplifiers Q206 and Q207 is connected to terminal 16 of component board A201 through switch S202 (contacts 6

and 5).

NOTE

In this condition, contacts 9 and 10 of switch S202B connect terminal 5 of transformer

T203 to capacitor C215 to apply an ac ground.

(2) Transmit operation. When the handset push-to-talk switch is pressed, ground is applied through resistor

R225 to terminal 5 of relay K201 and causes the relay to energize. Battery voltage is connected through switch

S202B (contacts 10 and 9) and relay K201 (terminals 4 and 2) to terminal 4 of component board A201 to provide

operating voltage for oscillator Q204. Switch S202B (contacts 2 and 1 ) connects the battery voltage to terminal 3

of component board A201 to provide operating voltage for audio amplifier Q205, and to pin J of P201 to provide

operating voltage for the preamplifier (Q201 and Q202).

c. TEL Position. With the TEL-RAD-RAD/SPKR switch in the TEL position, battery voltage is applied to the

preamplifier (Q201, Q202) during both transmit and receive operation. The voltage is connected from the battery

through switch S202B (contacts 10 and 7) to pin J of P201.

d. Battery Supply. The battery supply consists of six BA-30 D cells connected in series. Capacitor C215 is

used for ac decoupling of the battery supply.

NOTE

in the A-, B- and C- models the call lamp circuit is connected directly to the battery supply

side of switch S201.. (Refer to FO-2, FO-3 and FO-4, respectively.)

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