RoIP stands for Radio over the Internet Protocol and you can use this technology to connect remote radios over any distance, easily.
There are, of course, very complicated and elegant communications systems that do this already such as Echolink, D-STAR, Allstar, IRLP, Tetra and DMR/Mototrbo, but tonight I homebrewed my very own, modest private link in half an hour – and you can too!
If you have a rig with a packet data port and an external sound interface, such as a Signalink USB, then all you need is some software and a mobile phone, for example.
|Signalink USB Interface with FT-817 set to 2m FM calling|
|Zello app with PTT|
I used a fantastic free app called Zello. Zello is a walkie talkie emulator for your smartphone but also has a PC programme counterpart. The clever bit is that it has a VOX function with several adjustments for sensitivity and delay. My project enabled me to talk remotely over 2m using my smartphone!
So, by pressing ‘PTT’ on my smartphone and making a direct call to my computer, the VOX switch was activated on my Signalink USB interface and my FT-817 transmitted. When the squelch was opened on my ‘817 by the station I was talking to (and this is the clever bit) the Zello programme on my computer used its VOX feature to transmit back to my smartphone.
|Zello GUI on Windows XP|
|Zello VOX settings|
Now I know that Ham Radio Deluxe can be established to give full remote control over my rig, but that’s for another day. This is one solution to automatically link two radios that anyone can do.