Absolutely. There are the over driven afsk signals that show up as double
shift width, the ones that show up with reverse shift (maybe inadequate
unwanted sideband suppression), the fuzzy tones (although that could be multi
path causing the phase distortion), and transmitters that put 2khz of noise
around the rtty signal (maybe compression on afsk, or noisy SoundCard limited
by the transmitters ssb filter). Not to mention all the click like
interference each time there is a shift from mark to space.
The high resolution panadapters make it pretty obvious who's doing what.
Since its hard to be really sure during the confusion and clutter of a contest
maybe we should schedule a tune up session to go with the practice sessions
before the major contests.
Mark. N2QT
On Jan 8, 2013, at 2:22 PM, "Dave Hachadorian" <k6ll@arrl.net> wrote:
> I was running a 24" Panadapter on each radio throughout the Roundup. It was
> very obvious which signals were clean, and which were excessively wide. I
> would say 5% were excessively wide. A few were grossly wide. A number of
> non-rtty digital signals were also grossly wide.
>
> Dave Hachadorian, K6LL
> Yuma, Arizona
>
>
>
>
> -----Original Message----- From: Al Kozakiewicz
> Sent: Tuesday, January 08, 2013 11:39 AM
> To: iain macdonnell - N6ML
> Cc: Eric Rosenberg ; rtty@contesting.com
> Subject: Re: [RTTY] RTTY Newbie Questions
>
> It was meant to be provocative. Every complaint I've "seen" of splatter
> with a modern DSP generated FSK signals has been due to the complainers
> receiver, often an artifact of the same high end DSP design that generated
> the signal!
>
> The IC-756 Pro III, for just one example, will make it appear that strong
> signals have splatter 2 kHz away when using a narrow filter. Broaden out the
> filter and the "splatter" disappears!
>
> Al
> AB2ZY
>
> ________________________________________
> From: dseven@dseven.org [dseven@dseven.org] On Behalf Of iain macdonnell -
> N6ML [ar@dseven.org]
> Sent: Tuesday, January 08, 2013 1:17 PM
> To: Al Kozakiewicz
> Cc: Eric Rosenberg; rtty@contesting.com
> Subject: Re: [RTTY] RTTY Newbie Questions
>
> On Tue, Jan 8, 2013 at 8:18 AM, Al Kozakiewicz <akozak@hourglass.com> wrote:
>
>> 2- How does one monitor their own (FSK) signal to see how good or bad it is.
>>
>> **
>> A key question I would have is: if you find out it's bad, what are you
>> going to do about it? Buy a new radio? The only way to tell would be an
>> "old time" scope on the RF output of your transmitter.
>
> That strikes me as a rather odd perspective. If your signal is bad
> (splatting, causing QRM, etc,), you should:
>
> 1) STOP TRANSMITTING
> 2) Fix it
>
> There were WAY too many splattery signals in the RU, and some with
> horrible buzz and noise covering multiple kHz (probably AFSK with
> audio problems). We need to be more aware of the cleanliness of our
> RTTY signals, IMO.
>
> 73,
>
> ~iain / N6ML
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