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HF APRS using
300bps AX25 Packet Radio One of my other interests is APRS, but on HF. I occasionally use
144.800MHz FMN but find APRS on HF more interesting as it’s more dependant on
propagation and of course the distances are much greater. The main aim is to
plot and send messages to distance stations without any Internet involvement.
I use UI-view32 and UZ7HO’s soundcard modem. Ui-View is easy
to set-up and you can produce your own maps, but there are other options like
AGW Tracker & APRSIS32 which use online mapping sources. I prefer to
stick with Ui-View32 as I find its message handling easier to use. Andrei UZ7HO, has produced a superb soundcard modem similar in
operation to AGW Packet Engine, but it is easier to set-up and much more
sensitive under noisy conditions.
You can also choose different sound cards or as in my case
choose to use external soundcard interface like the Tigertronics Signalink
SL-USB interface.
Depending on the speed of your computer CPU you can add
multiple decoders making decoding of weak signals under noisy conditions more
likely. Screenshot of the modem decoding received packets from Andy
F6EWX, despite QRM from a constant carrier.
Andrei’s earlier versions were just single channel 300bps
modem, but he has now released a version that is dual channel (left &
right sound channels) and both channels can be set-up to be either 300 600 or
1200bps modems. Ui-View32
can be downloaded and registered from here > http://www.apritch.myby.co.uk/uiv32_uiview32.php?lang=english
UZ7HO
Soundcard modem and user guide written by Jon G7OMN can be downloaded from
Andrei’s web site > http://uz7.ho.ua/
Andrei is constantly developing and updating his
modem so check his web site often for the latest version. HF APRS frequencies. Allow +/- a few Hz depending which Tone Freq
standard, KAM or PK,
@300bps you are using. 10.147.6 USB, 14.103MHz LSB, 28.140 USB. |
