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RE: OLD Tube Pleasures
Subject:
RE: OLD Tube Pleasures
Date:
Fri, 14 Mar 1997 22:26:38 GMT
From:
robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization:
Society of Manufacturing Engineers
To:
tesla-at-pupman-dot-com
The =Esteemed= John Freau responds to Robert Michaels:
T>Robert, All,
T>Yes, truly there is another wonderful world of coiling in the tube
coil
T>realm, and you post many good reasons why this is so.
T>Having built a number of tube and spark gap coils, I'd like to make
one
T>comment:
T>Regarding constuction, set up and tuning, I always find tube projects
more
T>difficult and time consuming than disruptive coils. I'm speaking here
about
T>new designs, not replicating other's designs. In a spark-gap coil,
assuming
I stand partially corrected. Thank you. In the case of
=original= tube designs, the neophyte (especially) may find
them more difficult.
As a working (and long practicing) electrical engineer - born
and bred in the vacuum tube era - such is not so for me.
And nowadays, computer programs exist which make the process
duck soup: plug in the tube characteristics (or just the type
no.!) answer a few questions, and out pops a design.
T>an experienced builder and "normal" coil parameters, there are only a
T>few main things to adjust; gap, ballasting, tune point, and coupling.
T>And these adjustments do not tend to interact too much, at least not
T>to a "overly sensitive" degree.
Your point is accepted. I recall the posting of (I believe)
one Richard Quick on how he cobbled up a crude coil one
morning just to be able to have the ozone from it to
deodorize an old refrigerator.
BTW - Whatever happened to Mr. Quick? Was a
frequent poster. Usually more literate and
knowledgeable than most.
He used a .sig of "...throw another megavolt across
it". Did he throw one too many megavolts across
something? He is missed.
T>In the tube coil on the other hand, especially large (26" to 36"
sparks)
T>ones, adjustment and set up is super-critical. Yes, a quickly cobbled
system
T>may produce some sort of spark, but optimal performance requires a
[ ... ]
Agree. To an extent. Tube coils are by definition, sedate.
"26 - 36-inch sparks" are almost a contradiction in terms
in the realm of tube coils. =If= a person were intent upon
achieving such,
1) - I'd admire his ambition.
2) - Yes, it would be difficultly attainable
T>time-consuming, trial and error balance of; coupling, tuning, grid
T>feedback grid leak resistance, and also calculated or trial and
T>error matching of the tube to the power level, matching of tube to
T>tank impedance, etc. If just one element of this synergistic dance is
^^^^^^^^^^^^^^^^^
OOooo! I like that. You write with as much verve as I
do (almost).
T>out of step, the results can be disasterous -- one eye must be kept on
T>the spark while the other is observing the tube plates, and all the
T>while the ear is listening for the proper full-throated "power-roar"
T>which often heralds tube coil synergism and kick-butt output.
I think "disastrous" is a tad bit overstated. There are
things to watch out for in tube =and in= spark-gap coiling.
(But as said, I've never played in the "36-inch league"
with tube coils).
T>which often heralds tube coil synergism and kick-butt output.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Yeh! You do write with verve. (personally, I use OLX -
"Off-Line Express")
Regards,
Robert Michaels - Tough
Enough to Coil in - Detroit, USA