Apache TX-1 "RF Hiccup" Puzzle

[Glen Zook]

Don't use the 6146B unless you are prepared for more
problems!  9 out of 10 Apaches do not "like" the 6146B
which is a completely different tube from the earlier
versions.

The 6293 normally doesn't have any effect except to
last considerably longer when replacing the 6146 or
6146A / 8298 (has a "heavier" plate construction).
The 6146B / 8298A often will not neutralize properly
and causes some other problems in many of the rigs
that were designed for the older tubes.

Also, any 6146W with a later code date of between the
later half of 1964 and early 1965 (depending on the
manufacturer) will be the 6146B equivalent.  This is
due to the fact that RCA originally said that the
6146B was a replacement for the 6146 and 6146A / 8298
without any problems.  This, unfortunately, did not
"pan" out.  However, the military did not revert to
the 6146A equivalent for the 6146W but stayed with the
6146B.  Originally the "new" 6146W was supposed to
replace both the earlier versions and the newer
versions.

For more details on the 6146 family of tubes you can
go to either website that is listed at the end of this
message.  The article that appeared in Electric Radio
a couple of years ago and that has been reprinted in
several other publications can be found thereon.

Also, any 6146W made by the "Electronic Tube Company"
should be considered "suspect".  According to my
sources they made about 10,000 tubes for the military,
got paid, then went out of business.  After a couple
of years when the military started trying to use these
tubes they didn't work at r.f.!  Audio, maybe (like in
the modulator of the Johnson Viking Valiant) but even
at 80 meters they are "lousey"!

The "innards" of these tubes don't even resemble those
of a "normal" 6146W.  Unfortunately, these tubes have
been appearing in the amateur radio market for the
past few years, often at "rock bottom" prices.
Frankly, if the "deal" seems to be "too good to
believe", then believe that it is too good to believe
for those tubes have often turned out to be among
those made by Electronic Tube Company.

Glen, K9STH


--- Peter A Markavage <pmarkavage at JUNO.COM> wrote:

You might try "regular" 6146/A/W/B's to see if the
problem goes away.

=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco



__________________________________
Do you Yahoo!?
New and Improved Yahoo! Mail - Send 10MB messages!
http://promotions.yahoo.com/new_mail

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/HEATH.html