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[aprssig] APRS Messenger now has APRS over PSK-63

Chris Moulding chrism at crosscountrywireless.net
Thu Feb 18 10:20:47 UTC 2010


I've released the latest version of the APRS Messenger v 2.26 program.

The biggest change is that APRS over PSK-63 has been added. This has 
been tried
before with an add-on to UI-View but that had problems sending packets with
errors to the APRS-IS system. I've added a preamble, start and stop 
flags and a
strong checksum to each packet so that each received packet is checked 
as correct
before being sent to the internet.
The display will show all packets received even with errors so that weak 
signals
can still be read manually. A frequency hopping routine has been added 
to the PSK-63
receiver to allow rapid signal acquisition over a +/- 50 Hz range. A 
Tune option
allows the operator to send a carrier + 150 Hz in frequency to avoid
interference to other APRS over PSK-63 users. The program uses the PC 
soundcard
in a similar way to other digimode programs.

The program comes in three versions with different PSK-63 audio tone
frequencies, 700, 1300 and 2100 Hz.

The second change is the addition of a receive only Igate. All HF or VHF 
packets
received can be sent to the APRS-IS. If the connection to the APRS server is
lost it automatically retries 1 minute later.

Future developments will include a GPS option for mobile HF tracking.

If you want to try APRS over PSK-63 on HF I'm running an Igate on 10.1497
MHz. Set your receiver to a dial frequency of 10.1476 MHz USB with the 
2.1 kHz
version. Please note that the dial frequency is the same as used for 
existing HF
300 bd packet APRS so it will work with existing HF APRS set-ups. In the US
Lynn KJ4ERJ is also running an APRS over PSK-63 Igate on 10.1476 MHz.

The software is freeware and can be downloaded from the following webpage:

http://www.crosscountrywireless.net/aprs_messenger.htm

A Yahoo group for discussion on this and other topics:

http://uk.groups.yahoo.com/group/cross_country_wireless

See you on the waterfall!

73,

Chris, G4HYG

-- 
Chris Moulding
Cross Country Wireless (2009) Ltd
7 Thirlmere Grove, Bolton, Lancs, BL4 0QB, UK
Tel/fax: +44(0)1204 410626
Mobile:  +44(0)7752 391908
Website: http://www.crosscountrywireless.net
Company number 6780346 registered in England and Wales  




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