Dead carrier on 451.3625MHZ

[N9TBQ]

Trying to track down an issue on the above frequency in Sheboygan.
Search of the FCC database shows a terminated licensee (Baycom) in Stockbridge on Quinney road. A renewed license at the same location of WPQB994.
I noticed a strong -60dB signal when traveling south on 41 near Wittman Airport, and it continued relatively strong all the way to FDL. I can see this dead carrier at -80dB in Sheboygan at 200'.

Is anyone else in the area that can verify the dead carrier at 451.3625MHZ, near Oshkosh, probably Stockbridge, WI?

Thanks
NH

 

[RevGary]

At 05:15 Hrs. CST Feb. 16, I connected my movable yagi to the input on my service monitor and ran the antenna around a full 360 degrees from central Brown County. The strongest signal was + or - 5 degrees on a heading of 178 degrees from here and it sounds as if something is starting to break down, because there are some hints of power supply issues present in the signal at this hour.

IF it is BayCom, it's part of their regional trunked system... and as a Motorola Servicing Dealer, their tech staff should have been notified of this situation automatically by it's own computer monitoring system after the first repeater time-out period expired and the transmitter was still on.

 

[N9TBQ]

Interferer

RevGary,
I appreciate your findings! I will continue on with a triangulation method.

NH

 

[djeplett]

S3 here in New London on the ham rig. Pro97 decodes 0-20-255 R20 when switched to LTR trunking.

 

[N9TBQ]

Thanks DJE.
Thats S3 out of 9 correct?
Can you explain the 0-20-255? Is that control channel info or?

 

[WayneH]

Can you explain the 0-20-255? Is that control channel info or?

It's the LTR channel information. Sounds like a hardware problem if 255 is constantly being sent over the dead carrier.

 

[djeplett]

Thanks DJE.
Thats S3 out of 9 correct?
Can you explain the 0-20-255? Is that control channel info or?

Yep, S3 out of 9. Not very strong, but strong enough for the Pro97 to receive it with my Sputnik antenna.
The LTR decode is control info being broadcast with the signal. Like wayne_h said, it shows it's f'ed up.

 

[N9TBQ]

Wayne, can you provide any additional information on what 0-20-255 represents?
Id like to have a bit more information that I can detail before I approach the owner.
They are a Motorola dealer, so anything specific to Moto systems would help.

Thanks
NH

 

[izz]

I can hear it in the northern part of Ozaukee County too.

Link to the LTR system this frequency belongs too.

Scanner Frequencies: Baycom Trunking System, Chilton, Wisconsin

 

[Tim]

I'm by no means a scanner expert (Even though I have been scanning for nearly 20 years now), but this kind of sounds like an LTR Multi-net system. It is very similar to regular LTR systems, but they have a "control channel" like channel that you have to lock out. If I remember correctly this "control channel" never changes. Also, you can LTR trunktrack it either.

I believe there are still some of these systems around the USA in the public safety sector. I believe Chester County, PA and some county in Arizona has this type of system.


Tim

 

[RevGary]

Just an FYI -

I EMAILED the owner at 07:30 AM Monday Feb. 16 - and as of 05:30 AM Tuesday, Feb. 17 - it's still stuck ON. So much for the 'customer service' aspect of them checking their EMAIL inbox... or arrogance in not caring.

That type of system is designed for constant-on transmissions over a long period of time, so unless the cooling fans fail, or the dealer 'wakes up', this could be on for some time yet.

WPQB994 is licensed for 177 watt ERP from 44-00-59.0 N, 088-16-17.4 W on one of the highest points in Calumet County.

Perhaps an email to the FCC office in Park Ridge Illinois might net some results... or just leave it the way that it is and see how long it actually takes for the largest Motorola "Servicing" Dealer in northeastern Wisconsin to deal with it.

 

[N9TBQ]

Re

Revgary,
Thanks again, for the response and the follow up.
We will certainly be following up with the owner in the next few days. I just wanted to gather some additional info before calling them. Im unsure, but after looking at their FCC license, it appears they need to lower power for night time operations, maybe something to do there HAAT.
We are licensed for the freq in Sheboygan, so we should have some clout with the FCC/Baycom - should we find they are truly interfering with us.

Thanks for everyone's response
Neil

 

[wirr]

451.3625 appears to be the Multi-Net "control channel" for Baycom's Chilton LTR trunking system which is networked with their De Pere system. This transmitter has been on the air for years. The system is operating normally.

I couldn't find a license for 451.3625 in Sheboygan County.

 

[N9TBQ]

WIRR,
So a transmitter with dead carrier, no intelligence on it what so ever is accurate for Multi-Net?
Just curious?
Our license is WPLS516

 

[RevGary]

Just an FYI again - It is 16:15 Hrs my time Wednesday and it is still on. After monitoring for awhile this morning, I DID hear voice transmissions on that transmitter. A discussion about a bad hydraulic line on a front-end loader at a jobsite was taking place. If it is a "control transmitter" it probably shouldn't have voice comm on there as I understand the system.

Anyway, I emailed an amateur operator who I know in the Chilton area and he replied back awhile ago that he actually phoned the BayComm office in Appleton and was met with a somewhat sarcastic reply which I will not mention here. That was 9 hours ago and the channel is still hot.

 

[djeplett]

No problem. Let it burn up. Should be cool to see how long it takes.

Should we start a pool?

 

[RevGary]

Oops -

Now, where did I put those hotdogs and marshmallows ???

 

[wirr]

WIRR,
So a transmitter with dead carrier, no intelligence on it what so ever is accurate for Multi-Net?
Just curious?

There actually is intelligence on the signal; it is LTR signalling which is subaudible data. If you put a LTR decoder on this freq you will see, in addition to the 0-20-255 idle message, the LTR talkgroup IDs of system users who are talking on voice channels on the system; presumably these are talkgroups that appear on multiple trunking sites.

 

[WayneH]

Wayne, can you provide any additional information on what 0-20-255 represents?

As the other guys have mentioned the "255" portion of the message indicates idle data. It should never be transmitted continuously and is generally sent when the software is set to permit "beacon" announcements and it can also be sent when a callsign is supposed to be transmitted. The logic of an LTR subscriber radio is to ignore this command and look for other messages; so operation can still occur on this repeater even though the controller is freaking out. Maybe the controller attempted to send out the callsign but hung...who knows given the assortment of LTR controllers out there.

 

[N9TBQ]

So is it a general conclusion that its normal for the transmitter control channel to transmit 100%?

NH