[Collins] 32S-1 PLATE CURRENT

[Glen Zook]

Actually, when the 6146B is substituted for the 6146 /
6146A tubes in equipment that were designed for the
older type tubes, the neutralization can "creep". 
This usually occurs within just a few minutes, but it
can, occasionally, vary over a period of hours.  That
is why I always suggest for those people who insist on
changing out the earlier tubes for the 6146B family
try to neutralize.  Usually, they will not neutralize
properly.  However, sometimes they will neutralize and
then the neutralization will "creep" as the tubes
"age".  If that happens, the 6146B tubes should be
replaced with the older types.  If the neutralization
holds, then that particular piece of equipment will
work with that particular set of 6146B type of tubes. 
The next time around, there is always a chance that
the tubes chosen just might not like that transmitter
and again start causing problems.

Also, remember the problems with neutralization that
Collins had with the military insisting on using the
6146B equivalent 6146W tubes (manufactured after 1964,
those before mid-1964 were either 6146 or 6146A
equivalents) in the 32S3 series and KWM-2 series.  The
components in the neutralization circuit had to be
changed to prevent problems (like "burning up:!). 
This neultralization problem will occur in the 32S-1
and 32S-2 if the neutralization circuit is not
"upgraded".

If you haven't read the article on the 6146 family of
tubes that was published in Electric Radio a couple of
years ago, you can find it on either of the two
websites that are referenced at the end of this
message.

Glen, K9STH


--- "Dr. Gerald N. Johnson, electrical engineer"
<geraldj@isunet.net> wrote:

As far as I know there is no TIME stability problem
with the neutralization of 6146B. Some circuits don't
have the range because its capacitances are different
from the smaller tubes.

=====
Glen, K9STH

Web sites

http://home.attbi.com/~k9sth
http://home.attbi.com/~zcomco

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