BOEING377 wrote:

I have tried LOTS of DSP solutions for HF SSB and nothing works as well as the
Clear Speech speaker with built in DSP. I dont like the user interface (dip
swicthes) but the unit flat out works better than anything I have seen.
Curious, since it was orginally engineered by a small company with nowhere near
the engineering resources of ICOM etc.

What ClearSpeech will not do is take out heterodynes, at least weak ones,
and get rid of SSB interference that's offset in the direction of the sideband,
a notable condition because a linear brickwall filter takes it away completely.

In particular, it has no manual notch, and no brickwall filter. It's deficient
in adjustable linear filters, in other words.

What it does do is a good job of recognizing various forms of noise
interference on speech, and taking out the noise, sometimes spectacularly,
leaving the speech.

Or, in my case, bird calls from the backyard bird microphone.

So it's the noise reduction, or the non-linear filtering, that the ClearSpeech
has the edge on, much better than any other I've seen so far.

The Timewave 599zx takes out the noise but leaves the speech sounding muffled;
the JSP NIR-12 has a couple of noise reduction methods, one of which sometimes
works on ignition type noise better than the ClearSpeech but not often, but
neither of which I'd normally go to first.

The 599zx has the best adjustable linear filters, but alas only a single manual
notch; and the widest bandwidth (5khz) of the bunch.
--
Ron Hardin


On the internet, nobody knows you're a jerk.