Ted Bruce wrote in message
...
On Sun, 27 Mar 2005 19:50:10 GMT, "RadioGuy"
wrote:
Ted Bruce wrote in message
.. .
You mentioned that Heathkit used 6146's in virtually all of their
gear. That is a valid statement, but they used 6GE5 sweep tubes in
the lower price-point HW-series monobanders, including the ones for
MARS/CAP. It was a purely a matter of economics, I think. Retail
price aside, there had to have been more manufacturing volume on the
sweep tubes, because just about every family had a TV set.
I now have a 4B-line, and also a bunch of HW-series rigs. The 6GE5's
are fairly inexpensive even today, compared to 6146A's or W's or the
later GE 6146B's that Heathikit blessed.
73,
Ted KX4OM
Yup... for sure... I forgot about those monobanders. I even had one
myself---the HW-32A.
Well, you raise the question that's been on my mind for quite
awhile---just
what was the production on the 6146? I don't have the slightest idea how
to
find that tidbit. They were well in production before TV became
commonplace---maybe 10 years or so. Just what was the production figure
on
the 6JB6? To be honest the 6JB6 doesn't sound like a common tube. I
recall
the horizontal deflection amplifier tubes like the 6DQ5 and 6DQ6 but
looking
in my 1961 RCA tube handbook I don't seen the 6JB6 listed.
I recall, Kenwood had 6146's in their TS-520, correct me if I'm wrong but
wasn't it a 6146 of Japanese production ( I remember they had the shiny
chrome finish on the metal surfaces that typified some of the Japanese
parts)?
RG
You're right about the Kenwoods. I just sold a TS-530S that I bought
new in 1983, and it used 6146B's. It was rated at 220W PEP Input,
about 10% higher than the 6146/6146A rigs. I don't recall how the
finals looked. I opened the case only one time, to enable the WARC
bands. Boy, that was one fine radio! I used it for only 7 ARRL-log
pages worth of contacts, mostly some skeds with relatives and playing
around during contests. I kept it in a zipped up bag that you buy
pillows in. When I auctioned it, I packed it in the original double
box with the styrofoam inserts, and it looked brand new. I knew that
I would never be able to repair it myself, since it was a hybrid
mostly transistorized rig. So, I let it go, and bought an HW-101, and
got my Drake 4B line out of storage.
By the way, Glen Zook, K9STH is an authority on the 6146 family.
Check out his site at http://home.comcast.net/~k9sth/
Ted KX4OM
Hi Ted... I lost myself in this thread... well, that's how it all got
started. I was going through my Drake stuff when I looked at my tube spares;
sets of 3 matched 6JB6's for the TR-4. The price I paid at AES for each set
back in the late 70's was marked on the packages---$18.00 and they are going
for nearly $100 today! My mind wandered to the 6146's and the question was
born---why didn't Drake use the 6146's instead of those sweep tubes?
Decades back those 6146's seemed to be everywhere. Heck, I had a bunch that
I was given not to mention what I collected here and there. You are right,
the matched 6JB6's cost more than the $20 I quoted but I tried to be fair
and compared a single 6DQ6 to a single 6JB6. Looking at what a matched set
of 6JB6's cost for my TR-4 they seem closer to $30 each (the last time I
checked).
Through the course of conversation I began to feel that Drake used those
tubes to increase their profit margin since they were available nearly
surplus (no longer used in TV designs) at $0.50 apiece (based upon what I
read somewhere). I tried to find the relative quantities produced; 6JB6's
compared to the 6146. I think we ended up somewhere that there were many
more 6146's made than the 6JB6's---so the price... classical economics
rules. If the tubes used in the Drake gear were 6146's, more than likely
they would go for around $10.00 each (I've seen them go for around $6 to
$7). Its interesting to reflect that with all the amateur rigs out there
that used the 6146; from the Ranger I and the KWM-2 (and who knows what
else) maybe ending somewhere with the Kenwood gear of the 80's, the price of
the 6146 has effectively escaped the price escalation that seems to have
affected the 6JB6.
Anyway, I found some interesting articles on the web; QST (1980) by Doug
DeMaw and in 73 (1975) by a young Dave Ingram (now of CQ magazine). The
articles present design information related to the use of sweep tubes in rf
power amplifiers. I'm sure the boatanchor group would like reading through
them, besides, you just can't miss Doug's 2-meter amplifier using two 6JB6'
s!
http://www.thermionic.org/sweep.html
Thanks for the link. Yes. that article on the family of 6146 tubes was
informative.
RG