West mountain, Timewave DSP and ssb....
I operate cw quite often. I have an autek that is really good with cw. SSB is not too impressive. Do the other audio dsp filters such as the timewave and westmountain do a good job with ssb? I have a kenwood ts 130s...
All the audio filters I've ever seen are more impressive on CW than SSB. That said, I have an MFJ-784 that helps peak up weak signal SSB so that it's understandable. I just replaced it with a Timewave 599zx which is even better. In both cases, the noise reduction helps a lot as well. The Timewave can also narrow down a CW signal almost to the signal width without ringing, which is really useful.
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I had a Timewave 599 years ago, and it did work on CW very well, but I didn't care for it at all on SSB. I never found the Timewave to be as good as the built in audio DSP on my IC-746, and not in the same class as the IF DSP on my IC-7000. I recently acquired an old Ten Tec Omni VI+, and I think it's noise reduction as as good or better than any I've seen. It actually makes signals that I can't copy (on digital modes) fully readable, and actually makes SSB sound better, or at least no worse than without the noise reduction.
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Another vote for audio DSP units do really great things to CW, RTTY and DATA when connected to a unit that has no DSP of it's own. I have a MFJ-784B and it's does a great job on these modes. Now for SSB it can help but you have to know what to do to get it there and even then the improvement isn't very impressive in comparison to what it can do to the narrow modes. On SSB the automatic notch is really great. Anybody who thinks their carrier is going to cause you a problem is sadly mistaken. The only thing that might happen is your receivers AGC may reduce the signal. That's where the AGC in the MFJ-784B comes in and levels everything back to exactly the same volume as before. It does this with very little noticeable audio effects. Of course this automatic notch is not a good one for the narrow modes so it automatically turns off when you select them.
Overall having an audio DSP is better than having nothing and as pointed out if you have a rig that has the latest DSP in the IF then the audio DSP becomes somewhat of a door stop.
Last edited by KO6WB; 06-18-2012 at 09:44 PM.
I've had tthe Timewave 599zx for over a decade.
I used it mainly for the filters with CW and RTTY,
mostly RTTY with a TS-940, before I bought an
IF DSP rig. It REALLY makes RTTY signals
"Pop" out of the background if set up correctly.
The filters are user programmable.
It also can function as an FSK or FSK RTTY Modem.
(With the Timewave proprietary Software0
ON SSB, eh, I really didn't see much advantage.
The noise reduction is pretty good at best, but then
again my unit is 10 years old and there must have
Another spiffy thing about the 599zx is that is has several
built in bench test applications:
Two Tone Generator for SSB linearity testing.
Audio Signal Generator: 20 Hz to 10 kHz in 10 Hz steps
CTCSS Tone Decoder
The millivoltmeter measures true rms and peak, as
low as 1 mV, and the sine wave generator output is calibrated in the same
units. The sine wave generator and the millivoltmeter operate simultaneously for gain and frequency response measurement.
And older models can be simply and
inexpensively upgraded to:
Function as a Sound Card Interface,
a nice backup for your stations main PSK equipment.
I use a West Mountain Radio CLRdsp unit. It has several levels of noise reduction you can choose from and I find it helpful on both CW and SSB. I'm usually disappointed by the onboard noise reduction capabilities of modern rigs. They do reduce the noise, but usually at a considerable cost. Either they sacrifice audio quality, signal level, or whatever, but there always seems be something lost. That's why I never use the DNR functions on most of my rigs. None of them are anywhere near as effective as the West Mountain Radio CLRdsp unit. And I used to say the same thing about my old Clearspeech Base Unit, but it sadly isn't working anymore. (Maybe I can revivie it....).