HOMING SIGNAL FLOW-continued

TM 11-5820-670-30

1-50. HOMING SIGNAL FLOW. (CONT)

The application of the dc signal to the vertical needle of the homing indicator provides the pilot with

information to fly left or right.

The if. signal in the if. agc amplifier (15) is applied to the homer signal strength amplifier (18) which supplies

a dc signal to the homing indicator horizontal needle.

The homing indicator horizontal needle provides a visual indication of relative signal strength which,

in turn, allows the pilot to determine if the aircraft is heading toward or away from the transmitting

station.

In the homing mode of operation, audio heard in the operator's headset contains some background

noise and does not have the same quality as in the receive operating mode. However, the voice

signals are intelligible and distortion is not noticeable unless the signals are of a very low level.

The radio set is capable of transmitting audio signals while the control unit mode selector switch is set

at HOME. If the push-to-talk button is pressed while the radio set is operating in the homing mode,

relay K4502 deenergizes and removes the output of the homing antennas from the input of the antenna

tuning and protection circuits of module A1100. Simultaneously, relay K4501 (not shown) becomes

energized and connects the communications antenna to the receiver-transmitter. Upon termination of

the transmit command, the receiver-transmitter will automatically return to the homing mode.

Squelch amplifier A5200 (19) supplies a flag alarm ground signal to the homing indicator. When the

received signal is of sufficient strength, the squelch amplifier supplies a ground to relay K5502 (not

shown), energizing it. When energized, this relay applies a ground signal to the homing indicator to

drop the flags. When the relay is deenergized, the alarm flags raise, indicating that the homing signal

is too weak to provide proper homing information to the homing indicator.

1-51