>
Skipp. Your attribution is bogus.
>Hello Peter,
>:From: Peter Sundberg <sm2cew@telia.com>
>:Gents,
>:It seems to me that no matter what anyone say's or present
>:about a DAF amp it is constantly being contested by the wise guys.
>
>This wise guy contested the signal I heard on 40 meters an
>adequate distance away, where I shouldn't have heard him.
>
>The typical round table with this gent had 8 other people, most
>running big amplifiers. I didn't hear much of anyone else. I moved
>down another few KHz and he still hosed up my conversation.
>It's fortunate that the operator is a really nice guy (and longtime
>friend) and took the amplifier off line when I brought it to his
>attention. A later conversation with him got me a copy of the
>screen control circuit he used. Maybe you guys would like to
>see it on the sonic server later this next week..? His heart is in
>the right place, his signal was not.
>
>:On the other hand, Rich can say that he once heard a "DAF"
>:amp that sounded bad and everyone is then certain that this
>:is the truth, un-contested. No matter the guy who ran this
>:so called "DAF" amp turns out to have his own "Dude-circuit"
>:to produce the doo-doo.
>
>Twas I who mentioned Norms amplifier, both Rich and I had
>many a conversation with Norm about the circuit. Rich convinced
>him to retrofit his circuit with something more conventional.
>Since I know what he used, let me tell you what was involved.
>
>A portion of the drive signal was used to control the screen
>current potential. His notes to me were for a dual 4cx250 amp.
>The circuit details show most of the work done with solid state
>devices although a tube equivalent was available.
>
>I'm under the impression one daf circuit actually uses rectified rf
>for the applied screen potential. This seems a rather odd arrangement
>to me as a portion of the actual rectified drive supplies the screen
>power. Norms circuit was a pair of hv transistors used to control
>the screen potential from a power supply. The circuit is a much higher
>z load on the drive source vs the daf circuit I've seen on the web site.
>
>Would this change the end result..? The dynamic screen potential is
>the tell-all. Both designs would probably place lots of "el torro
>poo-poo"
>in my receiver from 4KHz away. Norms did from Southern California to
>my QTH near Sacramento... a few hundred mile distance. The
>local HF CB'er's do it from 3 blocks away.
>
>:Running a DAF amp for a couple of years now I can say that it is good
>:design and I get NO complaints for splattering or sounding bad. (Using a
>:similar tube as in SM3BDZ amp, a QBL5-3500)
>
>If your blowing holes in the band, others might think you just
>another contest operator. If I heard you on the bands, I'd say
>something quick. Reference "The Emperors New Cloths" for
>a similar example. (Han Christian Anderson) Sorry, I had to
>say that at least once in my life...
>
>:Lars, SM3BDZ and Petter, SM3PXO has proven the linearity of the amp by
>:presenting plots on the Lars's webpage. We have used our amps on the air
>:for years without complaints. Can't you guys accept that... ??
>
>Plots didn't hold water for Norms circuit when we told him what everyone
>was hearing <4KHz away. Other than a few amateur circuits, why hasn't
>the daf circuit caught on in the market place..?
>
>:I think the DAF amp will be the Amp of The Millenium.
>:/Peter SM2CEW
>
>"Read my lips, no new taxes!"
>
>skipp
>
>
>________________________________________________________________
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>
- Rich..., 805.386.3734, www.vcnet.com/measures.
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