Tom Holden wrote:
Fred McKenzie wrote:

Pete, that's about as much as I paid for the receiver
I'm trying to improve! A Radio Shack DX-394

Tom-

I missed your original posting. What does the DX-394
currently use as an IF filter? If it happens to be made
by Murata (or maybe Panasonic), a replacement with better
specifications may available to fit in the same PCB
holes. Check your filter's part number with the
company's web site, and you may find a solution there.

However, if it uses the same filter for AM reception, a
tighter filter could reduce sound quality of music.

73, Fred, K4DII


Fred, thanks for your follow-up. The DX-394 has two 5-element Murata ceramic
filters, one 9kHz or wider for AM and one 6 kHz or wider for SSB/CW with a
BFO offset of +/-3.5kHz from 455kHz. That's why a narrower filter will need
a BFO mod. There does not appear to be a much narrower filter in the same
package and from what I understand Murata is out of the ceramic filter
business. So I guess I will have to keep an eye out for a surplus filter or
shell out $85 or so for a new 'economical' Collins!

Tom


You can probably find a surplus collins filter on ebay for about half
(or less) the cost of a new one. Fair Radio used to have 2.0 and 4.0
khz filters from the famous R390 receivers at about $25 or so.