I've done the product detector mod that converts the cathode follower for
the I.F. output to a product detector. Some BFO leakage, but it worked
pretty well. Right now, I've got a brand new looking R-388 that I am leaving
original.
As far as the mechanical filter update, the units I've had in the past seem
to have quite a bit of signal leakage around the narrower filters. The 6kHz
filter did work very well, though. Still, I like the earlier J series better
than the 51J-4.

Pete

"msg" wrote in message
...
Pete KE9OA wrote:

snip
Everybody seems to go for the 51S-1, not realizing that the 51Js were a
much better mechanical and electrical design.
A good testimony to this fact is that in the service center at
Rockwell-Collins in Cedar Rapids, they kept an old 51J-3 on hand as one
of their lab units.
snip

I also have a 51J-3 which is serving as a reference or lab receiver
(the back-end for other instruments, sensitive detector,
antenna testing, etc.) and as a benchmark receiver for comparisons
when testing other rigs.

BTW, what is your opinion regarding adding mechanical filters,
product detector, etc. mods to this rig (I have never found the
need but then again I don't use it for contesting)?

Regards,

Michael