[Collins] R-388/51J mods

[Jan Erik Holm]

My 51J-4 does the same thing on band 8. I´ve been measuring and
trying to find something wrong but just cant.
However by replacing the 6AK5 V101 with a 6BJ6 cures the problem,
with the 6BJ6 it works excellent on all bands. For the time
being this will be the fix, maybe I will look into it later.

73 Jim SM2EKM
------------------------------------
Dr. Gerald N. Johnson wrote:
>
> Me too. My 51J is squirrelly on 3 MHz. The RF stage oscillates if the
> antenna trimmer is peaked. Probably has to do with the way the antenna
> is coupled to that first stage grid.
> 
> Probably reported in some CQ article 23 years ago. Did google turn
> anything up? I'll try that next.