Eric, would you consider putting this info on the repeater builders web page...?
If that is not possible I'd like to have a copy ....thanks... John VE3AMZ ----- Original Message ----- From: "Eric Lemmon" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, November 21, 2004 5:20 PM Subject: Re: [Repeater-Builder] Help with circulator specs | | Joe, | | Actually, it's the opposite. The return loss will be maximum (highest | numerically) at the operating frequency, meaning that the minimum energy | is being reflected. It can be confusing to describe, because a proper | tuning of a circulator involves reversing the input and output for | making some tuning adjustments, and this reverses the readings. One of | the best procedures for adjusting a circulator is published by | Sinclair. I am sending you a copy in PDF. | | 73, Eric Lemmon WB6FLY | | Joe Ciarcia wrote: | > | > Eric thanks. If I looked at return loss, would the circulator operating | > frequency be determined by the lowest return loss? | > | > Joe | > | > At 03:01 PM 11/21/2004, you wrote: | > | > >Joe, | > > | > >I suspect that RJ Communications is no longer in business, so finding | > >tech data on that circulator may be difficult. | > > | > >The typical ferrite circulator doesn't dissipate much power itself; it's | > >the load(s) attached to the reject port that determines its power | > >rating. | > > | > >It's important that a circulator be correctly tuned to operate | > >efficiently. The label 140-180 MHz refers to the range of that | > >particular design, and should not be taken to mean that it will work at | > >any frequency in that range. Nearly all of the circulators I have taken | > >out of service from the 152 MHz band would not tune more than 2 MHz | > >either side of the frequency marked on the unit. I had to send them | > >back to the manufacturer to be reworked for operation on the 2m band. | > >This rework involved an exchange of magnets, pole pieces, and a new | > >garnet ground to a specific tolerance. | > > | > >A network analyzer is a must for tuning a circulator, especially a dual | > >circulator, since some measurements look for transmission peaks while | > >others look for return-loss peaks. A spectrum analyzer will not suffice | > >for this tuning task, unless it is used with a return-loss bridge. | > > | > >73, Eric Lemmon WB6FLY | > > | > >Joe Ciarcia wrote: | > > > | > > > I have a circulator from RJ Communications Products Inc | > > > of Scottsdale, AZ. It's a model HC-152. It also has a logo | > > > on it marked IJ. It has a marking tape on it which indicates | > > > that the freq coverage is 140-180 MC. Can anyone confirm this | > > > and know what the power rating might be? | > > > | > > > Thanks, Joe | > > > | > > > | > > > Yahoo! Groups Links | > > > | > > > | > > > | > > > | > > | > > | > > | > > | > > | > >Yahoo! Groups Links | > > | > > | > > | > > | > | > | > Yahoo! Groups Links | > | > | > | > | | | | | | Yahoo! Groups Links | | | | | | | Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
