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: <[email protected]> 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 <*> 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/
