(a) The TTY ON/OFF/SPKR ON selector selects voice (SPKR ON)
function of the amplifier-converter.
If SPKR ON is selected,
received voice signals are amplified and applied to speaker. If TTY
ON is selected, a teletypewriter connected at DC LOOP terminals (for
radioteletype operation through an internal TTY converter.
(b) The SQUELCH control controls the suppression of received
audio when no useful voice signal is present.
The OFF position
disables the circuit; rotating control clockwise increases the level
at which signals and noise are squelched. Desired setting reduces or
eliminates background noise between useful audio signal receptions
but does not make useful signals inaudible.
(c) The LOOP CURRENT control selects the desired adjustment
function of the converter.
The ADJUST potentiometer is for the adjustment of the
TTY LOOP current to 20 or 60 milliamperes (ma), as
read on the external meter.
The 20/60 MA SELECT switch selects 20 or 60 ma LOOP
CURRENT drives for the teletypewriter connected to DC
These can be sets required by the
The METER jack is for the connection of an external
meter to read TTY LOOP current.
The 3-amp fuse controls circuits in the amplifier-
The fuse can be replaced by removing the
(d) The teletype connections are the TTY KEY and DC LOOP
terminals. The TTY KEY terminal is for transmit only operation. The
DC LOOP terminal is for receive and transmit operation.
(e) The HANDSET jack is for connection of the handset for
voice or telegraph operations.
(f) The AUDIO jack is for connection of the audio cable to
the receiver-transmitter (except secure voice operation).
(g) The loudspeaker jacks are for output of received audio
Jack J5 is for connection of the control and power
Jack J6 is for connection of signal, control, and
Jack J7 is for connection of the RF signal cable to