Connect Systems Inc. -Model TP-154 Page 3
THE CONNECTIONS
Two connections must be made to the receiver and three to the
transmitter. Use shielded wires with the shields at each end
connected to chassis ground. (The rear panel barrier strip
terminals labeled "GND" are chassis ground). We recommend using
spade type crimp-on connectors for ease and reliability. Connect
the center wires as follows:
RX AUDIO: The audio input terminal should be connected directly
to the receivers discriminator (de-modulator) output.
RX COS: Connect to a point that has good voltage swing when
the squelch is opened/closed. The best point to
connect is to the collector of the transistor that
controls the busy light (if the receiver has one).
Otherwise, you may connect to the squelch gate
control voltage. Your last choice would be to connect
to output of the noise rectifier.
If the point selected goes more positive (voltage
increases) when a signal is received, strap JP-10
center to the + side. If the point goes to a lower
voltage, strap JP-10 from center to the - side.
When the COS threshold control P4 has been properly
adjusted (see page 5), and JP-10 properly strapped
(see page 6), the front panel RECEIVE LED will
illuminate only when a signal is received. This
condition must be achieved for proper operation of
the interconnect.
NOTE: The squelch control in the receiver must be set
for quiet (squelched) receive. Set the squelch as you
would any squelch, but remember if you set it too
tight receive sensitivity may suffer.
TX AUDIO: Connect to the transmitter audio input or Mic high
line.
PTT: Connect to the transmitter PTT line.
SUBTONE The SUBTONE output is used to inject DCS and CTCSS
into the transmitter. The injection point must be
after the IDC clipper circuit, and preferably
directly to the modulator.
NOTE: For CTCSS operation you may use either a phase
modulated or true FM (frequency modulation)
transmitter. However for DCS operation only a true FM
transmitter may be used.
