Anyone have white papers or info on how to modify/design cavities? What would it take to move a window 465 can to 445/435 tunable? What is the design parameters for the N connector straps? What is the design of existing tunable cans (L/C components)?
--- In [email protected], "Eric Lemmon" <wb6...@...> wrote: > > 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> > > > > > > > > > > >
