[R-390] building up a spare IF deck - filters?

[frankshughes at aim.com]

Hi,
I'm starting to put together a spare IF deck to use for testing & troubleshooting my R-390A (1958 all Motorola). 


I'm new at this hobby and am trying to learn as I proceed. 


I bought a scavenged 390A IF deck, all it has remaining on it are the transformers, tube sockets, 
electrical connectors.


The filters & BFO plus some other small parts are gone.


I found a BFO with no problem. (but no bracket or coupler) 


I have found some different mechanical filters? for sale in various places.


Not sure if I should get the standard Collins filters,
or are the Dittmore-Freimuth filters any better from a mechanical design?
?(is there any decomposing foam in the DF design?)


I have also found references to Dave Curry - Longwave Products filters, but they seem to be even more 
obscure than the D-F, so I'm guessing these are a very low probability to find.? 
(I have not found any of these for sale anywhere)


What is the actual operational effect, the functional performance difference between the
different manufacturer's filter designs? 


Is it worth the effort to attempt to obtain non-Collins filters?


Thanks,
Frank
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/r-390/attachments/20081215/88582270/attachment.htm