Would you want to believe 146.85 - 146.73 = 0.12 or 120 kHz? Neil - WA6KLA
---- Original Message ---- From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] That horrible noise Date: Fri, 21 Apr 2006 12:28:12 -0400 >Guys, > >I think you're missing one detail here. 146.73 minus 146.85 is 1200 >KHz. Twice the typical 2 meter split of 600Khz. > >I'm not sure EXACTLY why it's happening, but the math here has BAD >written all over it. Anytime you deal with multiples of your input >to output frequency separation, it's not a good thing. > >I wonder if the two repeaters are using the same PL tone? If so, >does one, or both encode that tone as well? > >This could help explain putting the repeater in PL not helping to >eliminate the interference. > >I think Ken is on the right track with an audio delay causing a >howl. It's not a necessity however because of the RF delay in the >possible feedback path. Realize that even at the speed of light >(in free space) RF transmission and reception are not >instantaneous. > >I think your best bet is to find a different frequency or location >for one of the repeaters if possible. > >Scott > >Scott Zimmerman >Amateur Radio Call N3XCC >612 Barnett Rd >Boswell, PA 15531 > >----- Original Message ----- >From: "Ken Arck" <[EMAIL PROTECTED]> >To: <Repeater-Builder@yahoogroups.com> >Sent: Friday, April 21, 2006 11:24 AM >Subject: Re: [Repeater-Builder] That horrible noise > > >> I'd be interested in hearing the wav file you recorded, Dave >> >> But bear in mind that your comment that it's not coming from either >> repeater could easily be wrong. As a matter of fact, if you're >running a >> delay in the audio path of either repeater, one of them is most >definately >> involved. It sounds like a typical spur/mix/intermod issue to me, >probably >> involving a 3rd party. >> >> Anyway, let's have a listen. >> >> Ken >> >> At 02:55 PM 4/21/2006 -0000, you wrote: >>> >>> >>>Two VHF repeaters in town have been bothered by this from time to >>>time.. The first, which only occasionally gets it, but gets it >LOUD >>>when it happens, is 146.730- The second (mine) at 146.850- is >>>getting it almost continuously now, but weak, ranging from "will >>>open squelch" (even with PL!) to "Will hold squelch but won't open >>>it" Unfortunately, it's putting enough energy out at low >>>frequencies that the PL board is seeing a tone, so PL won't save >me. >>> >>> >>>The noise has an echoing quality that I think is VERY distinctive, >>>but I can't figure where it's coming from. >>> >>>It's not happening in either repeater, we've had the opportunity to >>>completely shut down the machines when it's happening. >>> >>>The two repeaters are maybe 1000' apart. >>> >>>I've only started having a problem with it since replacing my >>>antenna so that I'm no longer stone deaf. >>> >>>I have a 5M wav file of the noise, if anyone's interested. >>>It sounds like broadband noise at first, but then you notice >>>the "feedback-ish" sound in it. At times we've heard what seems >>>like bits of audio in the noise. >>> >>> >>> >>> >>> >>> >>> >>> >>> >>>Yahoo! Groups Links >>> >>> >>> >>> >>> >>> >>> >>> >>> >> >--------------------------------------------------------------------- >--------- >> President and CTO - Arcom Communications >> Makers of the world famous RC210 Repeater Controller and >accessories. >> http://www.ah6le.net/arcom/index.html >> Authorized Dealers for Kenwood and Telewave and >> we offer complete repeater packages! >> AH6LE/R - IRLP Node 3000 >> http://www.irlp.net >> >> >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> >> >> >> -- >> Internal Virus Database is out-of-date. >> Checked by AVG Free Edition. >> Version: 7.1.375 / Virus Database: 268.1.0/269 - Release Date: >2/24/2006 >> >> > > > > > > >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/
