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Reviews Categories | Microphone Equalizers & Transmit Audio Accessories | DF4ZS RF speech processors Help

Reviews Summary for DF4ZS RF speech processors
DF4ZS RF speech processors Reviews: 15 Average rating: 4.9/5 MSRP: $65-130
Description: Increase average SSB power of radios without RF speech processing by up to 9 db without excessive distortions; smallest model fits into a microphone; make IC-706 or FT-100 sound like with a 400 W amplifier
Product is in production.
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PE1JLJ Rating: 5/5 Aug 6, 2006 00:49 Send this review to a friend
cool, worthwhile to get processor for your MH-31  Time owned: more than 12 months
after paying,the PCB got lost in the mail and Joachim sent me another one.

The voice characteristics can be adjusted a little bit with a different condensator if you like, at the front. The speech processor gives quite some "punch" and you'll have to watch the ALC at first not to overdrive you set.

I found it very peasing to work with; compared to original mikes, it indeed gives you quite a few more contacts.

Thumbs UP !
G4ZRZ Rating: 3/5 Jul 8, 2004 12:40 Send this review to a friend
OK but not with supplied mic element  Time owned: 3 to 6 months
I've had one of these for a few months now. I have to say that it really helps to increase signal strength. However the downside is that audio quality just isn't very good.

To fit the unit you are required to remove the stock element and fit a small electret element. The claim is that this gives much better sounding audio. It doesn't. The new element has far too much treble and has a edgy sound. After processing this is even worse. At first I thought it was just my unit but after listening to the sound comparisons on the FT817 yahoo group I can see that it's the same for others (who seem happy with the sound).

On SSB much of the harshness isn't apparent but on FM it's awful even without the processor turned on. I've tried adjusting the mic gain but it's no good. Before I did this mod I was always receiving complements about my FM audio with the stock mike, not any more.

I'd love to hear what this unit sounds like with say a Heil HC5 as the element or even with the stock mike element but I'm about to convert my microphone back and try a W4RT one big punch.
DL6XAZ Rating: 5/5 Jul 8, 2004 08:31 Send this review to a friend
excellent  Time owned: 6 to 12 months
Ordered and installed on unit in the MH31 Yaesu mike for FT817 - the result was simply amazing! Reports indicated at least one more S-units and a very clear modulation.
Based on this positive experience I bought another one for the FT857, improved version, and the results are the same.
Highly recommended for especially QRP equipment!
Service and delivery, documentation and support far above standard!
vy73 Fred DL6XAZ
WB6UQA Rating: 5/5 Dec 3, 2002 21:53 Send this review to a friend
Alot of punch for A 706  Time owned: 0 to 3 months
I ordered this miniature RF prossesor from Germany.I was worried it wouldn't drive my Icom 706,but I was wrong.I do not have to close talk my mike anymore,pleanty of punch.It will fit in any mike case,about half the size of A book of matches.I get very good audio reports when I talk 9 or 10 inches away.For $63 it delivers alot of bang for the buck.
73's Gary
NO9E Rating: 5/5 Oct 10, 2002 10:50 Send this review to a friend
Good punch at bargain price  Time owned: 0 to 3 months
I ordered a minature speech processor from DF4ZS. It came in about 2 weeks. The unit generates a 455 KHz SSB signal, clips it, and converts back. Amazing size for what it does. It effectively makes a signal of cheap radios (like IC706, FT-100) sound like with 400 W amplifiers at a fraction of cost and labor.
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