Subject: glowbugs V1 #211
glowbugs         Wednesday, December 24 1997         Volume 01 : Number 211


Date: Tue, 23 Dec 1997 15:38:47 -0600 (CST)
From: mjsilva@ix.netcom.com
Subject: Re: Stuff... (fwd)

>Will get Walt's stuff up on the web page ASAP. His regenny uses a #32 tube
>as the detector.  In my RCA tube manual, it is listed as a Sharp Cutoff
>Tetrode.  As far as I can find out, there are NO other sharp-cutoff
>tetrodes in any other configuration.
>
>So, does anyone know if it is possible to "make" a sharp-cutoff tetrode
>out of a sharp-cutoff pentode by simply connecting the suppressor grid and
>the screen grid together, or would that just "mess up the works"? 

There were a number of tetrodes, sharp- and remote-, "in the beginning", 
e.g. the 24.  After that the RF screen-grid tubes all became pentodes until 
they (tetrodes) reappeared again in '60s TV tuners as RF amps.  I'm guessing 
they were resurected because a tetrode has lower noise than a pentode (fewer 
elements = lower partition noise).

73,
Mike, KK6GM



Date: Wed, 24 Dec 1997 21:07:27 -0500 (EST)
From: "Roberta J. Barmore" <rbarmore@indy.net>
Subject: Season's Greetings! (some BA content anent cool tubes)

Hi!

   Well, here it is Christmas Eve, and as I am (as ever, these days) too
sleepy to head to the shack and play with high voltage, I'll use the lists
to wish a happy holiday season to everyone.  For all the fine old gear and
parts found, history shared, questions answered and questions raised, a
warm and friendly toast to each and every one of the friends gathered
here!

   "...Questions raised," yes indeed; the thread on tubes (usually
detectors) operated at less than normal heater voltage has been most
interesting.  I was asked about it private e-mail about the time the
thread began, and hazarded it was linearization trick (the tube in that
question being a diode); but the Drake 2-B does much the same thing with a
multigrid tube (or so memory doth insist).  So maybe it is for noise.  Did
anyone find a definitive reference?

   Merry Christmas and/or Happy Holidays, and the very best of New Years
to all!  (And will the Canadians and Brits *please* wear protective
headgear on Boxing Day, and suitable gloves, too!  ...It's cold out
there, and an Olympic rule besides).

   73,
   --Bobbi



End of glowbugs V1 #211
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