Kantronics KPC–3 Plus User Manual page 213

Pin 4: This pin is the CONTROL B output from the KPC-3 Plus which may be used as a
control line to your radio or other devices. It is an open-drain circuit, and will apply a
ground on this pin when controlled by the CTRL command in your KPC-3 Plus (not to
exceed 50 V dc or 200 mA). This pin can also be used as AN0 (Analog Input). See the
Jumper section for details.
Pin 5: Receive audio from your radio connects to this pin. This normally will connect to
the external speaker jack on your radio, but may connect to the receive audio pin on
your microphone connector (if available).
Pin 6: This pin connects to the ground of your radio mic connector.
Pin 7: This pin is not normally connected in the KPC-3 Plus, but may be configured as
an external reset or to supply power to the KPC-3 Plus using jumpers J6 and J7. See
the Jumper section for details.
Pin 8: This pin is the CONTROL A output from the KPC-3 Plus which may be used as a
control line to your radio or other devices. It is an open-drain circuit, and will apply a
ground on this pin when controlled by the CTRL command in your KPC-3 Plus (not to
exceed 50 V dc or 200 mA). This pin can also be used as AN1 (Analog Input). See the
Jumper section for details.
Pin 9: This pin is connected to ground as shipped from the factory. You may re-
configure this pin to perform an external reset by using jumper J5. See the Jumper
section for details.
Interfacing Hand-Held Radios
This section is for those who need more information than that given in the ―Installation‖
chapter.
Many transceivers, especially most hand-held models, obtain Push-To-Talk keying by
completing a circuit between the mic input and PTT ground. A direct PTT input to the
mic input line of units with this type electret condenser microphone is not usable without
some type of isolation.
If you plan to operate with a hand-held transceiver, the KPC-3 Plus has incorporated an
isolation circuit which is available by positioning jumper J9 on the center post and the
left post (labeled HT) as you face the front of the KPC-3 Plus. Should you later use a
different type radio, this change may need to be reconfigured by placing the J9 jumper
on the center post and the right post. Most other radios of current manufacture will not
require any modification of the KPC-3 Plus.
You may also interface to a hand-held without performing this modification by
incorporating the same type of circuitry in the cable from your KPC-3 Plus to your hand-
held. Ground return and speaker audio are both supplied through the external speaker
jack of your hand-held. While you will need to check the exact requirements of your
hand-held radio, the following guidelines may be useful:
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