Connection to Transceiver
The pin out for J2, an 8 pin interface connector is as follows:
1.
Receive Audio Output
2.
No Connection
3.
Tone Output
4.
Tone Detect
5.
Ground
6.
Hang Up / Xmit Input
7.
Audio In
8.
Power 4-15 VDC
The power required for the ToneLCD is +4 to +15 VDC at approximately 9
mA. The power lead, pin 8 of J2 should be connected to a convenient
switched supply within your transceiver. The return connection for the
power is on J2 pin 5.
In order for the ToneLCD to operate in a tone squelch mode, it needs to
sample the detected audio and provide a way to disable the audio path in the
squelched condition. The ToneLCD provides an open collector transistor
output that can be connected into your transceivers circuitry to enable or
disable the audio path. An easier way to take care of both the tone input and
squelch requirements is to connect the ToneLCDs audio in, J2 pin 7 and
audio out, J2 pin 1, in series with the hot lead of your rigs volume pot. The
ToneLCD has an audio switch in line with this audio path, and this switch is
deactivated by the ToneLCD firmware when the tone squelch is activated
and the correct tone signal is not seen. The connection in a typical
transceiver is outlined in the schematic shown in figure 5. If you have no
need for tone squelch, simply connect J2 pin 7 to the high side of the volume
