Kantronics KPC-2 - Hard Reset Procedure

Interfacing Hand-Held 5
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 KAM, KPC-2 and KPC-4 have
incorporated an isolation circuit which is available by jumper positioning. Should you
later use a different type radio, this change may need to be reconfigured. Most other
radios of current manufacture will not require any modification of the TNC.
You may also interface to a hand-held without performing this modification by
incorporating the same type of circuitry in the cable from your TNC to your hand-held.
Ground return and speaker audio are both supplied thru the external speaker jack of
your hand-held.
ICOM HT radios key the PTT by providing a low impedance path from the mic input
to ground. To accomplish this, simply install a resistor (approximately 3.9K seems to
be a good value) in series with the PTT wire from the TNC, and connect this to the mic
input along with the AFSK line.
AFSK سن󰾯
.1 uf
Icom Mic Connector
PTT
3.9 KQ
Yaesu radios are similar but use a mono plug and a different resistor.
Yaesu Mic Connector
PTT
2.2 KQ
Most KENWOOD HT radios key the PTT line by connecting the sleeve of the mic
connector to the sleeve of the earpiece connector. This means that you will not need a
resistor in the PTT wire from the TNC, simply connect the PTT wire to the sleeve of
the mic connector. Another point to watch - most of the KENWOOD HTs (2500 and
later) use a three pin mic connector. The AFSK from the TNC should therefore connect
to the RING and not the TIP of the mic connector.
Kenwood Mic Connector
AFSK Û
.1 uf
PII
HAND-HELDS 23
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Copyright
1989,
1990,
Kantronics,
Inc.
All
Rights
Reserved.
:
Duplication of this manual or the firmware without - Aug. 13, 1990 M ersion 3.0
permission of Kantronics, Inc. is prohibited. Installation Manual