OK, after a few months of scanning while working (traveling to Casey's in Pike/Cass/Brown/Adams/Morgan and many other Counties)
I have noted multiple NXDN transmissions, assumed bleedover, from Cass County's system. I have notes, I'll have to go though my whole notebook for the last 3 months, but will have to get it put together.
Some of the interference I got was just the scanner (or both scanners) just stopping on what seemed like a very narrow signal, that was often silent.
I have never heard anything for an extended period of time, except when literally in Cass County getting blasted by the signals.
I will update this more in the next few weeks, hopefully.
151.0075 Interference - Philadelphia (late July)
151.0025 Interference - Ashland (late june) [also heard on 155.0325, 152.6725]
(currently missing a month or more of notes)
So, in all reality, I don't think I found anything scanning on the road, or while in hotel at night. Just got some interference and some NXDN.
[QUOTE=jeatock;1967169]Need some help; I am chasing a source of interference on a Pike County Illinois Public Safety system frequency (151.130), and two adjacent frequencies.
Somewhere in NW Pike County, SE Adams or SW Brown (or points north) are fairly strong ‘rogue’ transmitters sending data bursts. Could be GPS position reporting or correction, or SCADA control data. Too short and regular for voice. One short second of “diesel engine noise”, sometimes repeating at random intervals, sometimes not at all. Seems to be more in the morning and early afternoon, and less as the day goes on. Sounds digital, but doesn’t decode as P25 or NXDN.
Omni-directional spectrum analysis shows three nice clean narrowband transmitters on 151.100, 151.115 and 151.130 at more or less the same time, not one wandering signal. Because of the brief and intermittent nature of the bursts, triangulation tracking has been tantalizing but fruitless.
Terry Weatherford, WX9SAR
IL / MO / MI - RR Database Admin