Surfin’: Send APRS Messages via HF PSK and GMSK
By Stan Horzepa, WA1LOU
This week, Surfin’ looks at new HF APRS applications originating from the UK.
In the APRS realm, there is something new afoot on the other side of the pond: the Cross Country Wireless APRS Messenger. This software that provides the means of originating an APRS message on VHF and have it transmitted on HF using PSK (Phase Shift Keying) or GMSK (Gaussian Minimum Shift Keying), specifically PSK-63 and GMSK-250 modes of those two modulation types.
Cross Country Wireless also has another APRS freeware Windows application: Cross Country Wireless HF APRS SDR (Software Defined Radio). This allows an SDR receiver to receive HF APRS transmissions on the 30-meter ham band. For more information, as well as a link for downloading, visit the HF APRS SDR Web page.
If you need an SDR receiver to mate with the HF APRS SDR software, Cross Country Wireless can fulfill your needs with their Wireless SDR Receiver. A review of a pre-production receiver appears in the August issue of the Radio Society of Great Britain’s RadCom; the RSGB is Great Britain’s IARU Member-Society. Cross Country Wireless has corrected the problems cited in the review (external oscillator input, 40 meter sensitivity, 30 meter sideband rejection) in the production versions of the receiver.
Until next time, keep on surfin’.