[R-390] 4kc filter repair?

[Don Reaves W5OR]

Roy mentioned the web site describing rebuilding a Collins mech. filter.
It was mostly in Japanese, although the pictures told the story.  
Unfortunately the original link is broken; there is a notice to check 
another site, but the filter article is missing.  I'll see if the author
will respond and revive his original pages.  

Another solution, proposed by George Rancourt was to compensate the
gain on the other filters.  Well, here is the original posting to
the list in 1998, I think.  Sorry, I lost the header to credit the 
author.

--snip--
I had a rather enjoyable conversation with George Rancourt (K1ANX) in
my quest for a Dittmore-Freimuth (EAC) IF deck. He passed along a
helpful tidbit regarding IF deck alignment when one of the mechanical
filters is a few dB's softer than its siblings. The filter which is
used the most tends to wear out and not pass as much signal. His solution
is to detune the rest of the filters slightly using the variable capacitors
across the filters to match the soft filter. Then increase the IF gain
of the entire deck to compensate.
--snip--

I think the original specs allowed only 1 to 2 db loss.  

Anyway, I think this might make a great on-going discussion topic, as
all our filters are due to become extinct.  I have some that rattle now with
what must be hardened foam bits.  

What is the *proper* way to get these things apart?

Don W5OR


> I can't remember who told about doing this but there is a web 
> site that 
> shows the process.  Now I cannot locate that web site.