The meter reads P-P just like the scope. I generally set dev with the meter and confirm it on the scope. But your right, this really doesn't matter. I was just making sure they didn't have the dev out of wack and from what I gather here they don't.
We're going up Tuesday with another repeater and the 8924c to check it out. I'll be looking to see what comes down the antenna. If there are no big signals that shouldn't be there, and we can see/hear the paging on channel, and I there is no activity on 151.14 (actually 151.145 is San Bernardino County) or 170.94 (ULS FCC DB shows nothing) then I'll assume it's a spur. I have talked to the tech and he was friendly. I'm going to contact him again and see if he will come up the hill with us and inspect his transmitter. -- Tim :wq On Aug 21, 2010, at 12:59 PM, MCH wrote: > There is something wrong with your SM, then, as it should not show a > deviation of 15 kHz on a signal that is 15 kHz P-P unless it's only > deviating in one direction from the carrier. > > The +/- 4 kHz sounds about right. But, it should be centered around the > carrier frequency of 157.740 (Or, on 157.736 and 157.744). It would also > equate to a P-P of about 8 kHz as there is nothing but a shifted carrier > involved. > > Regardless, I suspect none of this relates to your problem. > > If it's only 75 yards from you, I bet it's a very weak spur. It's likely > down far enough that it's legal, too. If that is the case, the only > thing that will solve it is putting a filter on its TX to notch your > repeater RX frequency (good luck getting that to happen if it's not on > the same site - and often if it is on the same site). > > Joe M. > > Tim Sawyer wrote: >> >> >> My service monitor (HP 8924C) has both a deviation meter and an >> oscilloscope to display the demodulated audio. Both the numbers on the >> dev meter and the peak to peak on the scope read about 15 Khz. >> >> I see another paging system (152.84) that shows the same 15 Khz dev, and >> a bunch of other ones that show 5 Khz dev. >> >> -- >> Tim >> :wq >> >> On Aug 21, 2010, at 12:18 PM, MCH wrote: >> >>> >>> >>> Before you said 15 kHz P-P (IOW bandwidth). Now you're saying 15 kHz >>> deviation. 15 kHz deviation would be way too high. >>> >>> Joe M. >>> >>> Tim Sawyer wrote: >>>> >>>> >>>> I haven't noticed a hum. There's more of a scream on it. >>>> >>>> It's POCSAG. Is that analog? >>>> >>>> The dev is basically 15 Khz but there is, what I going to call splatter >>>> that is like 30 Khz. >>>> -- >>>> Tim >>>> :wq >>>> >>>> On Aug 21, 2010, at 10:14 AM, MCH wrote: >>>> >>>>> >>>>> >>>>> Many times (but not all), there will be a grungy sound with the spur. >>>>> Think of a very loud 60 cycle hum. >>>>> >>>>> And 15 kHz is higher than normal. I think the typical shift is 5 kHz >>>>> (+/- 2.5 kHz) if we are talking about digital paging. Analog might >>> be 15 >>>>> kHz, as the bandwidth limit would be 16 kHz. >>>>> >>>>> Joe M. >>>>> >>>>> Tim Sawyer wrote: >>>>>> >>>>>> >>>>>> I'm not sure what you mean by grungy. What are you getting at? >>>>>> -- >>>>>> Tim >>>>>> :wq >>>>>> >>>>>> On Aug 21, 2010, at 6:59 AM, MCH wrote: >>>>>> >>>>>>> Does it have a 'grungy' sound to it when you hear it on your input? >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> ---------------------------------------------------------- >>>> >>>> >>>> Internal Virus Database is out of date. >>>> Checked by AVG - www.avg.com <http://www.avg.com> >>>> Version: 9.0.783 / Virus Database: 271.1.1/2746 - Release Date: >>> 03/14/10 03:33:00 >>>> >>> >> >> >> >> > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
