158.805 interference

[KidClerk]

I'm soliciting some help from all of you in northwest Indiana to try to locate the source of interference on our county fire/ems dispatch frequency of 158.805. We are getting a digital sounding transmission about every 65 to 70 seconds on this frequency. For those radios that do not have a PL, it is getting annoying. The signal is stronger at night and on some nights, even is picked up by pager. I've emailed some of my amateur radio friends in Illinois and two have responded from Loda, IL and Chebanse, IL that they can hear it, so its not as low power as I originally thought. It sounds as if it is a 'polling' signal. At first I thought it was our new water tower four miles north of town communicating with our pumping station but I found those frequencies and its not that. Ironically, I've heard this same signal on the same frequency in other parts of the state. Using my directional antenna I have narrowed it down to north of my location here in Brook, Indiana (Newton Co.). If anyone has the opportunity to listen and narrow the search for the interference down, several of my fire departments would be greatly appreciative.

Thanks!

 

[ecps92]

Is your system on a Repeater? If so don't rule out the input freq.
I've seem Tech's forget to turn the input PL/DPL back on

If no to the above, have you run a report from the FCC on who in your state and neighboring state are also licensed on this freq?

I'm soliciting some help from all of you in northwest Indiana to try to locate the source of interference on our county fire/ems dispatch frequency of 158.805. We are getting a digital sounding transmission about every 65 to 70 seconds on this frequency. For those radios that do not have a PL, it is getting annoying. The signal is stronger at night and on some nights, even is picked up by pager. I've emailed some of my amateur radio friends in Illinois and two have responded from Loda, IL and Chebanse, IL that they can hear it, so its not as low power as I originally thought. It sounds as if it is a 'polling' signal. At first I thought it was our new water tower four miles north of town communicating with our pumping station but I found those frequencies and its not that. Ironically, I've heard this same signal on the same frequency in other parts of the state. Using my directional antenna I have narrowed it down to north of my location here in Brook, Indiana (Newton Co.). If anyone has the opportunity to listen and narrow the search for the interference down, several of my fire departments would be greatly appreciative.

Thanks!

 

[pickles37]

Here is a list of all agencies with active licenses for that frequency in Indiana from the FCC ULS. Note that all of these are for analog voice emissions as far as I can see, so there shouldn't be anything digital (except for Washington City which has a NXDN digital designator). I suppose it could be coming from Illinois too...

1 KBU295 HIGHLAND POLICE DEPARTMENT 0002874162 PW Active 08/19/2012
2 KEP633 WASHINGTON, CITY OF 0002872380 PW Active 11/20/2021
3 KGY288 SOUTH BEND, CITY OF 0002895308 PW Active 04/19/2021
4 KJL709 EDINBURGH, CITY OF 0002874782 PW Active 06/07/2013
5 KNCL547 BLOOMINGTON, CITY OF 0012499489 PW Active 02/23/2015
6 KSN276 SELLERSBURG, TOWN OF 0002872851 PW Active 07/18/2013
7 WNBX348 NEW CASTLE, CITY OF 0002873362 PW Active 02/27/2015
8 WNQG217 NEWTON, COUNTY OF 0002885861 PW Active 03/19/2014
9 WQBC210 ALLEN, COUNTY OF 0002877660 PW Active 09/16/2014
10 WQEK742 Fairmount, Town of 0014386643 PW Active 02/22/2016
11 WQFU536 NEW HARMONY VOLUNTEER FIRE DEPT 0002886950 PW Active 10/05/2016
12 WQH722 INDIANA, STATE OF 0004978565 PW Active 03/30/2013

 

[KidClerk]

Checked the input. It's definitely on the output only.

While traveling Friday I found the signal to be very strong in the Williamsport/Attica area. I guess I was picking it up strongest on the back side of my beam antenna. It was weaker on the north and south side of this area, but I was unable to check it to the east and west.

Kyle

Is your system on a Repeater? If so don't rule out the input freq.
I've seem Tech's forget to turn the input PL/DPL back on

If no to the above, have you run a report from the FCC on who in your state and neighboring state are also licensed on this freq?

 

[SCANMUNCIE]

I found several using it in Illinois close to your area:

Chicago, IL City of Chicago Emergency Management - Tower at 65 feet - KJY777
Alsip, IL Alsip Village - - Tower at 72 feet - KRT727
Alsip, IL Worth Township - Tower at 53 feet - KVB425

Plainfield, IL - Will County - Tower at 98 feet and putting out 100watts - WNZY675

Looking at location of the towns you listed, I would suspect your getting it from Plainfield Tower site based on height and power output.


Hope that helps a bit..

 

[KidClerk]

Just an update....this issue has been resolved. The source was the city of Tilton, Illinois. They had hooked up a low power transmitter to the wrong antenna and were transmitting at a much higher output than they were supposed to be. A call to the local Motorola dealer in town was made and they tracked down the cause and corrected it.

 

[Anon6083]

Just an update....this issue has been resolved. The source was the city of Tilton, Illinois. They had hooked up a low power transmitter to the wrong antenna and were transmitting at a much higher output than they were supposed to be. A call to the local Motorola dealer in town was made and they tracked down the cause and corrected it.

Very glad to hear that you were able to source the issue. Congrats!