Not really. I had not seen this in any of my older catalogs, and I wondered if in fact the unit was made by Decibel Products. Like many RF products, ferrite isolators in particular, the frequency range stated in a manufacturer's catalog refers to the capability to construct- which is not the same as the field-tunable range of a specific product. I was curious if the window filter (AKA preselector) could be useful in the 70 cm Amateur band without modifying the coupling loops or jumper cables.
73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jeff DePolo Sent: Monday, May 31, 2010 6:09 AM To: [email protected] Subject: RE: [Repeater-Builder] Re: Help Needed (Guidance and advice) tuning a DB Products Duplexer Mine don't have labels on them. Usually they were sold as part of an SP package that included the window filters, multicoupler, etc. I haven't tuned or swept this particular set, but from experience, the cavity resonance will tune over a wide swath, probably the full 406-512 MHz, but the loop lengths may not be optimal over such a wide span (depending on how the cavities are being used), and likewise, the cable lengths will vary. You have something in particular in mind you want me to test? --- Jeff WN3A > -----Original Message----- > From: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > [mailto:[email protected] <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of Eric Lemmon > Sent: Sunday, May 30, 2010 12:29 PM > To: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > Subject: RE: [Repeater-Builder] Re: Help Needed (Guidance and > advice) tuning a DB Products Duplexer > > > > Jeff, > > Can you positively identify the window filters by part > number? Also, what > is the useful frequency range of the units you purchased? > > 73, Eric Lemmon WB6FLY > > -----Original Message----- > From: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com> > [mailto:[email protected] <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of Jeff DePolo > Sent: Sunday, May 30, 2010 8:39 AM > To: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com> > Subject: RE: [Repeater-Builder] Re: Help Needed (Guidance and > advice) tuning > a DB Products Duplexer > > <snip> > > I bought two sets of those window filters from the same guy, > but I knew what > they were, caveat emptor is the golden rule at Dayton or any > other hamfest. > Actually I think I gave him $75 for the pair, and I took the two > cleanest/newest ones he had (the newer dark-tan ones). > > --- Jeff WN3A > > <snip> > > > > >
