I've got an MFJ204 antenna bridge that's sickly. It has bands A thru
D. Bands
A thru C work just fine. However, only the upper portion of Band D
works
(usually between 19MHz and 35MHz). But, between 11 MHz and 19 MHz the
oscillator is usually dead. I can sometimes get it to spring to life
with just
the right setting of an attached antenna tuner (or by dancing around
the room
with aluminum foil on my head), but those techniques should not be
required for
factory approved operation.

It appears that the only Band D specific component is an inductor.
However, I
think the band switch works by placing additional inductors in
series...so the
Band D inductor is always in the circuit, even for Bands A-C.
Therefore, I
don't think it's the inductor.

Any ideas why the lower portion of Band D might be dead and what I
might look
for?

Details of my efforts can be viewed at http://wa5psa.blogspot.com/
(warning...this web page should not be viewed by someone with a low
tolerance
for watching someone "learn" by mistakes).

Brad