Are 8950's good on 6m?
Hi David,
The answer is yes. But it's not cost effective. When the tubes fail or
fade, their replacement via the NOS method isn't worth it. You'd be much
better off going with another tube that's more practical to find/replace.
New-NOS 8950's go for as much as $60 each when you can find them without
an argument.
Sell them on the used market and buy a set of the Svetlana sweep tubes if
they'll go up that high. Check the ratings on the EL-509 or similar.
Real world AM power out is about 40 watts per tube, staying within the
practical safe zone. SSB and low duty cycle modes will allow much more.
Some circuits in operation pass drive power through to the output. You
can push them harder in operation, but their lifespan is quickly reduced.
Yes, the 8950 was designed as an RF sweep tube. Very popular in the
Palomar Amplifiers (calm down guys, I'm almost through this) and the last
Swan HF radios sold off the line.
There was also a very popular conversion from the Swan 350 (three drifty)
which used 6HF5 tubes to the 8950 for increased power out. The mod was
published in an ARRL Hints and Kinks article which also made it into the
book by the same name and source (the white covered version). The mod
increased the power output and provided reduction in un-wanted RF
products.
Last to mention, the 8950 has 12 volt filaments.
OK, that's it.
73's
skipp
http://sonic.ucdavis.edu for Southpark and other fun.
http://pilot.ucdavis.edu for the TRS-80 home page.
From: "DavidC" <davidc@bit-net.com>
I am thinking of modifying a 10m amp built with a pair
of 8950's for 6m ... are the 8950's good for 6m, please?
How about for AM? (I have read that they were designed
by GE specifically for RF service, not kludged from TV.)
Thanks! & 73, DavidC K1YP
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