[RTTY] best hardware RTTY decoder?

[WS7I]

Good point, Joe.  And reminds me that years ago I built a conversion
for my ST-6000 which uses one impedence I think 600 ohms and changed
out the input to 8 ohm transformer so it would match.  Made things
work much better.  Used the ST-6000 to feed a PK-232 for a number of
years to get "real" filters.

ST-8000 is nicer will take from 8 to 10K ohms and balanced or
unbalanced.  Switch selectable.  See page 25 of the manual.

Same caveat is also true of AFSK audio as well.



On Tue, Aug 31, 2010 at 3:09 PM, Joe Subich, W4TV <lists at subich.com> wrote:
>
>
>  > Many hardware and software decoders are cheap enough to warrant
>  > running in parallel on the same signal which provides the strengths
>  > of each, as conditions vary.
>
> There is one caveat when running multiple decoders on a single receiver
> - be certain to do it in such a way as the receive signal (audio) is
> distributed equally to all decoders - including the soundcard.  It is
> very easy to find that one device has a lower input impedance than
> others and "hogs" the audio ... or that one device requires a lot
> less drive than others and overdrives easily.
>
> A less obvious problem that can "color" any comparison is operating
> the devices at a "compromise" audio level that fails to make effective
> use of each decoder's dynamic range.  With a compromise input level,
> some devices may be driven into distortion prior to the A/D converter
> while others may be operating in an area of low A/D resolution.
>
> An audio distribution amplifier with individual level controls for
> each output is almost mandatory unless all devices have individual
> preamplifiers and their own (hardware) input level control.  The
> input level (drive) to each device should be adjusted so that the
> maximum signal level is slightly (6 to 10 dB) below the input clipping
> point to make the best use of each device's dynamic range.
>
> 73,
>
>    ... Joe, W4TV
>
>
> On 8/31/2010 5:29 PM, Ed Muns wrote:
>> Dick, K7VC, wrote:
>>> I would like to thank everyone for their inputs on the best
>>> hardware RTTY decoder.
>>>
>>> As good as these units are, I have detected what seems to be
>>> an undercurrent of opinion that even the best are still using
>>> decade-old technology and the best modern software solutions
>>> are surpassing the best hardware solutions.  Am I reading this right?
>>
>> Depending on how you define "best", this conclusion will be correct or not.
>> RITTY is decade-old software technology that is superior to most other
>> software and hardware decoders in some signal detection scenarios.  What is
>> important to you?
>>
>> * only weak signal detection
>> * realistically available decoders
>> * non-zero-beat signals
>> * signals buried in QRN
>> * pile-ups
>> * nearby loud signals
>> * multipath
>> * flutter
>> * all conditions with equal probability
>> * etc.
>>
>> Many hardware and software decoders are cheap enough to warrant running in
>> parallel on the same signal which provides the strengths of each, as
>> conditions vary.
>>
>> Ed - W0YK
>>
>
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-- 
Jay WS7I