[AMPS] Loudenboomer History

[John Brosnahan]

>I read the Loudenboomer stories with great interest. I'm under the
>opinion there were three or four different amplifiers made with the
>"Loudenboomer Label". One or two were the ones previously mentioned here
>as a Magazine construction article and the commercial product which I've
>never seen any info on.
>
>The above amplifiers used a 4Cx1000, the previous post didn't seem to
>mention the tubes these amplifiers used.
>
>Then I've seen one or two articles about Loudenboomer amplifiers which
>used different tubes. One in particular had a glass tube, possibly a
>4-1000.  This amplifier was brought to my attention by a former
>operations manager of the local Vocal Facility (Navy portion).  He asked
>me for a Loudenboomer diagram as his was lost. When I presented a copy of
>the Magazine article, he later told me his amp had a different tube. 
>Possibly the Loudenboomer label was used by other folks.


Obviously Lee, W0AIW/W0AR, is the best source for info on this and when
I saw him at Friedrichshafen this summer he was sharp as a tack.  He even
recalled minute details of a CQWW CW contest that I operated from his station
in 1962 as a M/S with K0LFY/N1GL.  BTW  Lee was a mentor of mine and got me
my first electronics job at Wilcox Electric during the summer between high 
school and my start at Missouri School of Mines at Rolla (W0EEE) that same
year.

The original Radio Industries "Der Loudenboomer" had a single 3-400 in the
final.
And you correctly recall the 4CX1000A amplifier that was also called the
"Der Loudenboomer".  It was published in QST in 1960 by Lee and was a group 
project by some of the members of the Kansas City DX Club.  Radio Industries
did the fab work for 7 or 8 of these units and Lee had one in his station that
he used on SSB.  But Lee also had five other  "Der Loudenboomer" amps
in his station that were single band amps that he used on 80 through 10
on CW.  These had a pair of tubes and I think they were actually 4-250s
rather than 4-400s but I am not absolutely sure which tube was used.

Of course when Lee sold Radio Industries to Hallicrafters they brought out
the  "Der Loudenboomer" amp under the Hallicrafters name.

I do seem to recall a single 4-1000 amp called the  "Der Loudenboomer" but
I BELIEVE it was just a use of the name as a generic term for an amplifier and
didn't have anything to do with Lee's work.

The 4CX1000A amp in QST is a real classic and is a lesson in amp design--
especially the use of a tetrode in a grounded-grid circuit.

73 John  W0UN


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