The enterprising ex-secretary of my club, Brian VK6TGQ coordinates an “experimenters net” most Sunday mornings in Bunbury wherein different aspects of Amateur radio are played with. Over the last month or so they have been experimenting with sending Slow Scan TV over 2m simplex. From this distance I have not been involved in this apart from occasionally joining them on the IRC channel to see what they are up to.
The equipment to do this can be pretty basic. They started out just with an app on their phones, to transmit, the app loads the image and plays a series of tones (FSK) as each line of the image is transmitted. If you don’t have a cable into your transmitter, you key the transmitter and hold the phone speaker up to the mic. A similar arrangement is possible for receive – the phone is left near the transceiver speaker and converts the tones (and any nearby noises) back into an image. Crude, but results are possible. A much improved result can be obtained by connecting the transceiver to the decoding device (usually a computer tablet or smartphone). Continue reading