Actually it probably would of been better if I measured in octaves, but that would of taken too long and not of been so simple.
Just currious, Do you have a AM radio station on 590, 600 or 610KHz in the vincinity? On 4/21/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > Only 10 dB ??? > > Neil > > ---- Original Message ---- > From: [EMAIL PROTECTED] > To: [email protected] > Subject: Re: [Repeater-Builder] That horrible noise > Date: Fri, 21 Apr 2006 09:40:34 -0700 > > >Scott, your math is off by +10dB. > > > >On 4/21/06, Scott Zimmerman <[EMAIL PROTECTED]> wrote: > >> 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 > > > > > > > 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/
