I see it mostly used during contesting, and hardly ever for long “rag chewing” contacts. While RTTY has a long history in amateur communications (refer to (refer to Wikipedia for details) it is hardly ever done with vintage equipment anymore, with software replacing vintage teletype terminals. I’ve wondered how to tune fldigi to minimize that effect, but I haven’t figured it out yet (I’m not much of an RTTYer). The squelch control that it has is slow to stop the decoder, and often at the end of a transmission you’ll see a bunch of garbage characters. You can see that fldigi has some problems with putting out garbage letters, mostly at the end of transmissions. If you configure it to use the stereo mixer output of your PC as input, you can use both programs together to decode the RTTY. Spectravue doesn’t have an RTTY decoder built in, but fldigi does. This is the view using my SDR-IQ running Spectravue. If you are using a radio which has a “waterfall” display like are common for software defined radio, you might expect to see the following: RTTY looks like two discrete tones, separated by around 170 Hz. I’ve left this uncompressed, so in theory, if you have any software that can decode RTTY, you can play it back and see what it says (I use fldigi). There is apparently some contest going on, as I observed people exchanging sequence numbers and signal reports. I recorded the following minute of audio using my SDR-IQ this morning around 14.090 Mhz, on the 20m band.
Is that too esoteric for you? Well, here’s some sights and sounds.įirst of all, here’s the sound. On the amateur frequencies, these tones are typically 170 Hz apart, and sent at 45.45 baud. It encodes text as a stream of five bit code words using a system known as Baudot, and then sends these codes as two tones using frequency shift keying.
I’d describe radio teletype (RTTY) as a popular digital mode, particularly among contesters.
Over at the tymkrs blog, they’ve been learning a bit about RTTY as a digital mode, but I found their description a bit theoretical.
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