[Amps] 1 tube or two ??

[EP Swynar]

Hi Jim,

I guess the question that REALLY begs to be answered, is simply, "...How
much overkill do you really feel you need in order to satisfy whatever demon
it is inside you that might compel you to even ponder such a thing?" Hi Hi.

Face it: a 4-1000A is LOAFING at Amateur Radio power limitations --- TWO
4-1000A's would loaf along even more under Ham power rules...

BUT! In the latter scanario, you ARE cooking (and aging) the filaments of
TWO tubes in loaf mode, versus just the one...so, my revised answer (I
guess) would be there's no advantage whatever in running a pair of them,
because you're needlessly reducing the life spans of two tubes, when one
will more than do the job at hand...unless you have a bushel basket full of
the tubes, & just don't care.

Besides, with one tube there'd be no need for having matched pairs...I also
recall reading someplace once where a single tube is always desirable over
any multitude of tubes in a design, for the sake of reduced distortion in
the final output...but then again, that could just be another "...urban
myth" that has morphed into reality within our Ham psyches...

I think you're question would perhaps have been better worded thusly: "I
want to run a kilowatt input: would it be better for me to run, say, a
SINGLE 3-500Z, or four 811A's to accomplish the task?"

~73~ Eddy VE3CUI - VE3XZ



----- Original Message ----- 
From: "Jim Isbell, W5JAI" <jim.isbell at gmail.com>
To: "kenw2dtc" <kenw2dtc at comcast.net>
Cc: "EP Swynar" <gswynar at durham.net>; "List for Amplifiers"
<amps at contesting.com>
Sent: Sunday, February 11, 2007 2:16 PM
Subject: Re: [Amps] 1 tube or two ??


> It seems no one really read my question.
>
> "Is there an advantage of one over the other if both are run at the
> limit for the Ham Bands?"
>
> I clearly stated "at the limit for Ham Bands."  Therefore two tubes
> does not have an advantage in power.  Both circuits can run at maximum
> legal limit without strain.
>
> Now is there an answer to the original question???
>
>
> On 2/11/07, kenw2dtc <kenw2dtc at comcast.net> wrote:
> > "running at full tilt, the two-tuber would have a whopping(!) 3 db.
> > advantage over the single 4-1000A!
> >  That's a full half S-unit difference"
> >
> > That's  a true statement.  Interesting that in today's world of inflated
> > S-meter readings with circa 2004-2007 receivers it may be  impossible to
> > double the power and get just a half an S-unit meter change.
> >
> > 73,
> > Ken W2DTC
> >
> >
> >
>
>
> -- 
> Jim Isbell
> "If you are not living on the edge, well then,
> you are just taking up too much space."