nt: Friday, August 29, 2008 3:29 PM
Subject: Re: [Drakelist] T-4XB neutralization?
For what it's worth, I have found the Sylvania by far are the best but I
have found no matter whether its a Sylvania, RCA, or GE, they all will
neutralize in the transmitter as the circuit was designed by D
I also found that GE's will drop off more on the Hickock 6000 when dropping the
filament voltage down a notch, Sylvanias and others barely move.
73, Gary___
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Ron -
No doubt that Sylvania was/is the best. Zenith branded tubes were ALL
made by Sylvania as well, so they are fine. RCA tubes worked fine, and
were often subbed in new production transmitters. The few times I used
GE tubes in the 60's I found them to drop off about 10% from "new"
outp
August 29, 2008 1:39 PM
To: [EMAIL PROTECTED]; drakelist@zerobeat.net
Subject: Re: [Drakelist] T-4XB neutralization?
I have 10 more matched sets of NOS 6JB6s to try. So far,
I've tried one pair from Sylvania, 1 pair of RCAs and 1 pair
of GEs and could not neutralize any properly. No obvious dip
"WA3WOM" <[EMAIL PROTECTED]>;
Sent: Thursday, August 28, 2008 11:09 PM
Subject: Re: [Drakelist] T-4XB neutralization?
> Mike -
>
> Before you expend too much effort in this, do you have ANY tubes that
> will neutralize? The RCA and Sylvania tubes were very close t
: [Drakelist] T-4XB neutralization?
I use GE's in my T-4XC and they neutralized easily without modification, with
the variable cap near half meshed (pretty good). Oddly, I had RCA's that I
could not neutralize. But by the 1970s it was hard to tell who really made what
tube. Look for a
I use GE's in my T-4XC and they neutralized easily without modification,
with the variable cap near half meshed (pretty good). Oddly, I had RCA's
that I could not neutralize. But by the 1970s it was hard to tell who
really made what tube. Look for a series of dots by the tube number
stamp. Tubes
Mike -
Before you expend too much effort in this, do you have ANY tubes that
will neutralize? The RCA and Sylvania tubes were very close to the
same and either should neutralize without difficulty or changes. I HAVE
used GE tubes without difficulty also, aside the from fact that they
seeme
Mike -
I haven't had to do that to one, but I would start with 5 pF, then 10 pF
if necessary. Be sure they are at least 2 kV caps, which is going to be
the hard part. They also need to be NP0 or 0 TC.
The trimmer cap is 2.7 - 8.4 pF, or a delta-C of 5.7 pF. The T-4XC had
a 6 pF parallel c
BlankA Drake technical bulletin issued when Drake could no longer get Sylvania
6JB6s and they had to begin substituting GE brand ones, says the following:
The T-4X series transmitter uses a 6 pf @ 2KV padder capacitor (C-48) across
the neutralization capacitor (C-49). You must experiment with a
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