[R-390] Mech filter REPAIR

[Tim Shoppa]

Several here and elsewhere have disassembled the mechanical filter
cans and made some nice pictures of the contents. Wonderful work.

Some have done a good job of reattaching single wires that had broken
off. Wonderful work.

Has anyone actually, say, completely disassembled a filter, put new
foam in, rewound a burnt in the middle (not just a reattachment)
coil, and reassembled the whole shebang to make a working filter?

Right now I'm with exactly the right number of working filters to
match all my radios, but I have several "bad" ones that have
accumulated over the years.

I compare the situation today with where Dallas Lankford was writing
about PTO's in the 80's. He clearly understood that there were
problems with PTO's that had gone beyond the endpoint adjustment or
needed an overall resetting at the corrector stack, but hadn't
quite gone as far as doing that. And now today there's a couple
websites that have really pristine pretty pictures of the true
innards of a PTO, where daring souls have gone in and completely
cleaned up and recalibrated from scratch. Those pictures and
details let me do the same a year or two ago when I rebuilt my
sludged-up PTO. Similarly there are websites showing how to
really do a complete teardown and clean of a RF deck today.

TMaybe I should stop being frustrated and open up a mechanical
filter repair shop, doing all the experimentation that I want others
to do myself and showing the results!

Tim