[RTTY] Signals that don't decode

[John Becker]

I'm not a big contester, but I enjoy RTTY and will occasionally work a 
RTTY contest for a few hours. I'm running FSK on an FT-1000MP Mk. V with 
WinWarbler. Since first getting on RTTY in 2008, I've worked 319 DXCC 
entities, so I think my setup is working pretty well.

I have noticed very occasionally specific stations that I am just unable 
to work even though propagation and pileup size suggest they should be 
easy. I have had them tell me to quit calling because they can't copy 
me. Since they don't know my call, I can't be 100% certain the remarks 
were directed at me, but timing suggested that they were.

In the ARRL RTTY roundup in January, this happened with a YV5. He came 
back to me as KM9G a couple of times, then said there was something 
wrong with my signal. Several years ago, I had the same problem with a 
D44 in the CQ WW RTTY contest. In both cases, I would come back to 
calling the station every so often, but never worked either one. There 
have been a few other instances of this, but these are the two which 
have stuck in my memory.

This is very frustrating and I wish I could figure out the cause. There 
must be a subtle incompatibility of some sort. Any ideas? Thanks!

73,

John, K9MM

rtty-request at contesting.com wrote:

> Date: Mon, 12 Feb 2018 16:20:04 -0000
> From: "David G3YYD" <g3yyd2 at btinternet.com>
> To: <rtty at contesting.com>
> Subject: [RTTY] Signals that don't decode
>
> I found during the CWWPXRTTY contest at the weekend that there were some
> signals with so much jitter on them that would not decode at all. They all
> sounded very similar with similar shaped spectrums. I am wondering if there
> is some software and in this case maybe it is radio firmware rather than a
> general purpose computer software that is generating this signal.
>
> I had one guy who kept calling me fortunately he was weak so I just kept on
> running and copying others.
>
> Does anyone know what this might be? Better still if someone has a sound
> file of the TX being received then I would love a copy of that sound file to
> have a look at.
>
> Thank you for those who gave me a Q and hopefully a new prefix at the same
> time.
>
> 73 David G3YYD aka M7T in contests