[1000mp] MP Roofing Filter from INRAD -- hiss reduction needed?

[Thomas Beltran]

> I like to listen to SW broadcast and would want the wider filter, but I
> also like the 4 khz, so maybe one of our innovative ham  brothers will
> come up with a remote switchable scheme.  Maybe a reed relay rtv to the
> board someplace  wired to the AF reverse button on the front panel, I
> don't use that function anyway.  I'm sure there are other
> possibilities.
>
Rob Sherwood, of Denver (Sherwood Engineering) came up with a very elegant
solution to switchable first IF filters for the Drake R-4C receiver.  It
works great - he has a board that uses TO-5 relays - it gives switchable
600hz and 2.0 khz first IF filters with separate First IF filters for USB
and LSB which can be cascaded with the passband tuning for a total of 16
poles of filtering.  He did this back in the 1970s.  When we get more
information, I'll check with Rob.  My guess is that most on this list are
familar with Sherwood's stuff, but if not here is the link.
http://www.sherweng.com/ham.html  There may be some application for the MP.
Tom W6EIJ