I wrote a little dos program years ago to design helical resonators. If anyone is interested.
http://members.cox.net/wd0fyf/files/helix.zip The zip file contains a program for helical resonators and one for helical antennas. They use no disk access, have limited error checking, no help and were meant for publication, but are usable. Gerald Pelnar WD0FYF McPherson, Ks ----- Original Message ----- From: "Mike Perryman K5JMP" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, October 26, 2006 4:42 PM Subject: RE: [Repeater-Builder] Re: DB4032-8A Decibel Six Meter (low band) Duplexer >I can save you a bunch of time... go to this website > http://www.members.cox.net/xsamo/01duplex.htm > > maybe it will save some duplication of effort.. > > 73 > Mike > K5JMP > www.k5jmp.us > > > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] Behalf Of DCFluX > Sent: Thursday, October 26, 2006 4:41 PM > To: [email protected] > Subject: Re: [Repeater-Builder] Re: DB4032-8A Decibel Six Meter (low > band) Duplexer > > > How big are the helicals? I am guessing that you have a 5" square > chamber about 7" or so long with .25" hollow tubing coils in the > center for about 7.5 turns. This would be approximently 375 ohms coil > impedence. > > Also how are the coils coupled? Are they taped going into a connector? > > Of course another thing is the use of 1/4 wave cables between section > which will give about 6dB of 'help' at the target frequency each, and > the stubs should be good for 20dB each. > > On 10/26/06, skipp025 <[EMAIL PROTECTED]> wrote: >> After you move it into the basement work area, draw out a diagram >> like the one I'm giving out. Measure and record the cable lengths >> and we'll have the information to compare. My duplexers are on >> 39.5MHz from the factory so your 45MHz unit will be the perfect >> next step measurements moving up toward 50 MHz and higher. >> >> cheers, >> skipp >> >> > "Steve & Peg" <[EMAIL PROTECTED]> wrote: >> > >> > I have one of these duplexers, rescued from being disposed of as >> scrap, and some information about it would be helpful/useful. I do >> intend to use it for 6M, when I get around to it, hopefully this >> coming winter season. I have heard through a friend that for best >> performance on 6M a turn may need to be shorted in each can. I >> haven't tried it yet though. I suspect I have to shorten the stubs >> and cables between cans. I am going from 45 to 51 MHz. First thing >> that I have to do with it is move it out of the garage and into the >> basement work area. >> > >> > Steve KB3FPN >> >> >> >> >> >> >> >> >> Yahoo! Groups Links >> >> >> >> >> > > > > > > Yahoo! Groups Links > > > > > > > > > > > > Yahoo! Groups Links > > > >
