The operating controls on the front panel of the test fixture-continued

TM 11-5820-509-35

input voltages to the test fixture and the module.

+24 volts power input to the module to determine the

circuit current drain.

(2) POWER ON lamp. This indicator is lit

when power is connected to the test fixture and the

(7) MODULE CURRENT meter. This 0- 150

POWER ON-OFF switch is in the ON position.

millimmeter indicates the dc current drain of the module.

(3) POWER 24 VDC 1/2 AMP fuse. This

(8) VOX ON lamp.

This indicator is lit

protective device is connected in the +24 volts dc

whenever the PTT ON-OFF-MOM ON switch is placed

primary power circuit to protect it from overload.

to ON or MOM ON.

(4) PTT ON-OFF-MOM ON switch.

This

(9) SIDETONE GATE ADJUST control. This

toggle switch enables the transmit mode in the module

potentiometer varies the sidetone gate bias applied to

when placed in either the ON or MOM ON positions for

the receiver amplifier circuit of the module.

simulated voice operation.

(10) Test jacks and binding poets are provided

(5) KEY ON OFF-MOM ON switch. This

for the attachment of signal leads and test equipment

toggle switch enables the transmit mode in the module

and are self-explanatory.

when placed in either the ON or MOM ON positions for

c. The piece parts required for fabrication of the

simulated telegraph operation.

test fixture are listed in the following chart and

(6) +20V/ +24V switch. This rotary switch

suggested parts placement is shown in figures 6-17 and

places the MODULE CURRENT meter in series with

6-18. Schematic diagram (fig. 715) illustrates the

either the +20 volts power input to the module, or the

internal circuit of the test fixture.

6-38