[Boatanchors] 6146B

[peter markavage]

Absolutely Jim. My Apache has a crude "neutralization wire" that comes up
through the chassis between the 6146's, that you manually move closer or
further away from either tube. I believe CQ or QST also had an article on
DX-100 mods that included adding neutralization. If you have a rig that's
running 6146's, and it has no neutralization adjustment, you should
figure out a way to add it. It's also not clear to me, why, after doing
neutralization to a final at a high enough frequency with B's, it won't
"hold". At least I've never seen that happen, but then again, I don't own
any Collins transmitters. I didn't think there was "creepy" capacitance
in those tubes.

What really should be done, is that someone should take the initiative to
gather the data for rigs that exhibit problems with B's or W's in the
final and define a resolution or fix, so that going forward, people can
use the data to resolve the issue if they perceive they have a problem
using them. The answer, don't use them, shouldn't be the answer. But,
then again, "do you feel lucky today", works for me at times.

Pete, wa2cwa

On Thu, 8 Dec 2005 10:52:45 -0600 "Jim Wilhite" <w5jo at brightok.net>
writes:
> I put 6146Bs in my B&W5100B and reneutralized it.  It works just fine 
> and 
> have not had problems.  Remember most manuals say to redo the 
> neutralization 
> when changing finals anyway.
> 
> On radios with no neutralization that is different.  The DX 100 can 
> be 
> modified to add neutralization, the Valiants have it.  Don't know 
> about any 
> others but it shouldn't be a great problem to add..
> 
> 73  Jim
> W5JO
> 
> 
> 
> > Many of the older transmitters actually did not have
> > any means for neutralization of the 6146 final(s) and
> > that definitely adds to the problem.  If the 6146B
> > tubes can be neutralized and if that neutralization
> > "holds" then they can safely be used in the older
> > transmitter.  Unfortunately, not every transmitter
> > "holds" the neutralization.
> >
> > It would have been a lot better if RCA hadn't used the
> > same basic nomenclature with the 6146B and if they
> > hadn't originally said that the 6146B could replace
> > the earlier versions without any problems.
> >
> > Glen, K9STH
>