>
>-Snip-
>
>> 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.
>
>As Colin, K7FM correctly states; There is one *important* difference. The
>time
>constant in Norm´s screen circuit was way to slow !!
>
>> Would this change the end result..?
>
>It most certainly would!
>
? Norm tried various time constant screen supply configurations. The
one that produced acceptable distortion was a 350v shunt regulator. The
3/2 power rule is undoubtedly true.
>>The dynamic screen potential is
>> the tell-all. Both designs would probably place lots of "el torro
>> poo-poo"
>
>Now, if your only reference is one guy ....
? There were two DAF users. .
>......with an appearantly flawed design -
>then this truly is a "paper brain statement" !
>
>
>> :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...
>
>Guess you would gain a lot if You work on your arguemental technique...
>
? Anderson's story of ''The Emperor's New Clothes'' is about denial. It
applies in this case since all DAFers must deny the 3/2 power rule.
DAFers must also deny what happens to linearity when the grid of a
grid-driven amplifier goes substantially positive. .
>
>Finally, I´m no salesman of the DAF amp and I really dont care if you
>never ever think
>of using that circuit. For me, the whole idea with this issue was to maybe
>learn something
>as this is supposed to be a knowledge based reflector. I´m in doubts...
--
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