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Re: ClearSpeech v. TS-2000



I tried playing with noise reduction from ChromaSound and was pretty
disappointed. It is a sound card dsp program. It reduced noise but the audio
was never "good", and readability didn't improve. When listening to signals
close to the noise level, my ear did a MUCH better job of copying than
ChromaSound.

So, at this point, the software solution hasn't appeared, but it is a great
idea. ChromaSound did fine with stronger signals, reducing operator
fatigue...but in terms of bringing signals out of the noise or suppressing
noise when the signal was relatively weak, it failed miserably.

The performance I heard on Jon's site was much better by the ClearSpeech
than what I heard from ChromaSound.

You can download the program yourself and try it. It runs unregistered for
15 min or half an hour...can't recall, so you can evaluate it for yourself.
Just do a google search ...it's by the same guys who wrote ChromaPix, which
to my experience is the creme de le creme of SSTV cound card programs. I've
had it registered for many years and it's a great program. Unfortunately,
ChromaSound doesn't live up to this standard.

...hasan, N0AN

----- Original Message -----
From: <K5OE@aol.com>
To: <amsat-bb@AMSAT.Org>
Sent: Sunday, February 23, 2003 9:02 AM
Subject: [amsat-bb] ClearSpeech v. TS-2000


> I carefully compared the files from Jon and Scott (thanks, guys) to the
Noise Reduction 1 mode (SSB) on my TS-2000 and find:
> - stronger signals, say 6 dB or more out of the noise, are about the same
level of improvement... less background noise, improved clarity, but some
slight compression and distortion to the audio.
> - very weak signals, near the noise floor of the receiver, show better
improvement on the ClearSpeech than on the Kenwood.  In fact, I don't find
the Kenwood NR1 to be helpful at all for very weak signals on SSB.  It is
just the opposite on CW using the Kenwood NR2 algorithm--as this one pulls
out stuff I can't copy by ear.  NR2 is too narrow for SSB.
>
> My setup for NR1 on AO-40 (not the same as for HF):
> - NR1 ON
> - LOCUT filter 500 Hz (HF set to 200)
> - HICUT filter 2400 Hz (HF set to 2000)
> - RX EQUAl (menu 20) CONVEN
> - AGC ON (set about mid-point)
>
> My biggest question is:  when will the sound card programs surpass these
dedicated gadgets?  My guess is within the next year.  After all, this is
not magic, but state-of-the-art programing using digital signal processing
techniques.  Just like objects in your rear view mirror, the software
defined radios are closer than they appear :-)
> 73,
> Jerry, K5OE
>
> ----
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