The ICOM IC-2720H does an excellent job of
supporting APRS / Packet and voice simultaneously with its dual band
capability. |
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Tom Webb, WA9AFM/5 Provides these tips
on using your IC-2720 for APRS and Packet:
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It is possible to run APRS / Packet and voice with
the 2720.
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The 'left' panel needs to be selected
as 'main' band, |
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You must select the 'right' side of
the panel for packet (Initial Set Mode actions, see page 62 in manual);
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this will force packet to the
'sub' band on the right. |
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voice operations will be on the
'main band' on the 'left'. |
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Set the packet speed for 9600 baud
(see page 69 in manual). This will accomplish three things;
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The mike will be muted during
packet transmissions and thus, you won't have to unplug it.
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During voice operations, data
transmission will be suppressed and voice will have priority;
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Flashing 'S1' will appear in the
lower right corner when transmitting on voice. |
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**NOTE: you can still run
1200 baud packet -- the 9600 baud setting enables the 'dual mode'
option. |
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I use the Byonics TinyTrakIII.
(but this should follow for other TNC's)
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Using the mini-DIN 6-pin connector,
the cable doesn't require data out
(* you will need to use Data out
for 9600 baud or the AF out for 1200 baud -
there are two audio
outputs -- choose the one for your baud rate *)
PIN |
SIGNAL |
FRONT PANEL VIEW |
1* |
Data
in (audio in) *see page 62 |
2 |
Ground |
3 |
PTT |
4 |
Data Out - 9600 Baud Only |
5 |
AF
Out - 1200 Baud Only |
6 |
PSQL (carrier detect) |
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| If the TTIII is powered up
before the 2720 the yellow CD light will come on steady.
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When the 2720 is powered up, the
CD light will go off and only come on when a signal is detected.
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You will get de-sensing on voice from
the APRS transmissions, but it's a fair tradeoff as you're using one radio
and antenna. I've been using this configuration for several weeks
with great success |
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* See p. 62 for
details on how to toggle data speed between 1200 (AFSK) and 9600 bps (G3RUH,
GMSK). |