Control Voltage Polarity Measurement

TM 11-5820-489-20

TO 31R4-2GRA6-32

Control Voltage Polarity Measurement

q Connect the telephone lines between the control units.

q At the remote control unit, turn the SELECTOR switch to the left-hand write-in position

and press the push-to-talk switch.

q At the local control unit, use Multi meter AN/URM-105 to check the polarity of the dc

voltage at the telephone line ends.

NOTE

To be sure there is enough line current for operation of the local control

relays, the voltage between the two binding posts should be between 24

and 45 volts.

q At the remote control unit release the microphone push-to-talk switch and return the

SELECTOR switch to the TEL position.

q At the local control unit connect the positive wire of the telephone line to the LINE L-1

binding post and the negative wire to the LINE L-2 binding post.

C. Push-to-Talk Operation of the Radio Set.

q At the remote control unit turn the SELECTOR switch to the left-hand write-in position.

q At the local control unit turn the REMOTE switch to the SET-1 position.

q Set the main power switch of the radio set for remote control of power, if it is so equip-

ped. If the radio set is not equipped for remote control of power, turn on power locally.

See the Technical Manual for the particular radio set being used.

q At the remote control unit, press the handset push-to-talk switch. At the radio set loca-

tion, check to see if the radio set is being controlled (transmitter and/or power control).

q At the remote control unit, turn the SELECTOR switch to the middle write-in position

Press and hold the push-to-talk switch. At the radio set location check to see that

transmitter is not transmitting and/or power has been turned off.

q If these requirements have been met, the line connections are correct. If they have not

been met, reverse the line connections at one of the two units and recheck.

A potential as high as 45 volts exists at the binding posts of both units,

when the push-to-talk switch is pressed at the remote control unit.

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