The SFP series is 4 elements, the SFR series is 6 elements. The 6 element filter has steeper skirts, so is preferred, but may be a bit more expensive.
The suffix letter indicates the 6 dB bandwidth. Filters scavenged from a DX440/ATS803A were the SFP450I and SFR450K. The SFP450I works great. I think it is a 6 kHz bandwidth filter. The SFR450K is better suited for SSB, as it is very selective, but leaves the audio quite muffled sounding in AM mode. The DX389/ATS909 has SFP450I and SFR450J filters in it. I haven't tried the SFR450J yet, but I suspect it would be just about ideal. It gives good selectivity without mufffling the audio too badly in AM mode on the Sangean radios, anyway Also, none of these are drop in replacements for the stock filter on the M37V, so they have to be jury-riged into the unit. On Jan 24, 2008 10:19 AM, Pete Taylor <[EMAIL PROTECTED]> wrote: > Mike Westfall, > > Re the mod for the SRF M37V, in your Jan. 4 E-mail you said we should > use either the SFP450I or SFP450J ceramic filter whereas in your > current E-mail, you specify the SFP450J only. I'm not a techie, so > pardon my ignorance, but are these interchangeable, allowing us to go > for the cheapest one? -- Mesa Mike LA de NM _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: irca@hard-core-dx.com
