[GreenKeys] Getting RTTY on the air

[kn7sfz]

Hi Harold,

I think RTTY has been relegated to below 3600 now...sniff.....

I believe there might still a RTTY group (RATTSNET) that meets in the 
evenings on the left coast here on 3598, LSB.  I quit listening to them 
when they changed to Olivia, so I dunno if they ever changed back.

I'm sure some of the other gurus here on the list can fill you in on  
your technical queries.

Keep us updated!

Richard kn7sfz in Orygun

On 11/10/2020 6:59 PM, Harold Hallikainen wrote:
> I've finished connecting my model 15 to the TU-170 to my radio (
> https://w6iwi.org/SEA245/ ). I added an audio transformer and a reed relay
> to the TU-170 to drive the SEA245 tri-state audio bus. For testing, I'm
> trying to get the RTTY decoder on a KiwiSDR ( http://rx.linkfanel.net/ )
> to decode my signal. So, here are some questions.
>
> 1. I remember from MANY years ago, that LSMFT, or Low Space Makes Fine
> Teletype. That, as I recall, is on RF, and it's reversed on AFSK. So, the
> TU-170 uses 2.125 kHz for mark and shifts up 170 Hz for space. That
> indicates that the transceiver should be set for LSB to get the signal
> right side up. Is this correct?
>
> 2. How is the transmit frequency normally specified? I can think of
> several ways:
>
> a - Mark frequency
> b - Center frequency (Mark frequency minus 135 Hz)
> c - LSB "carrier frequency" (Mark frequency + 2.125 kHz
>
> Is one of these correct? If so, which one?
>
> 3. What are common frequencies on the HF bands for RTTY? From many years
> ago, I think I remember 3.635 MHz for the mark frequency.
>
> 4. Anything special in the FSK settings on a KiwiSDR? Should the signal be
> inverted?
>
> THANKS!
>
> Harold
>
>
>

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