Monsanto / SkyWarn 147.36+ behavior...

[rjvalenta]

has anyone else noticed that the amateur repeater at 147.36 (i know it as the Monsanto ARC repeater, not sure what it's called now), seems to... randomly kerchunk over and over with an odd sound, then be idle for a while... then do it again? is there a distant repeater causing this? anyone know?

richard
n0tzc

 

[hkrharry]

It may be a digital voice mode, like DMR or Fusion, or even D-star.

Can you post a sample of the noise/signal?

HH

 

[kruser]

has anyone else noticed that the amateur repeater at 147.36 (i know it as the Monsanto ARC repeater, not sure what it's called now), seems to... randomly kerchunk over and over with an odd sound, then be idle for a while... then do it again? is there a distant repeater causing this? anyone know?

richard
n0tzc

The 147.36 repeater has had this issue for at least two years now. I also noticed it a couple years ago.
They moved SkyWarn off the repeater and made the 146.910 repeater the Primary SkyWarn repeater for the St Louis area over a year ago.

I'm not positive of the actual cause but it sounds to me more like a badly tuned or improper duplexer or cavity filter at the repeater itself where its own transmitter gets back into the receiver and keeps keying it up. Sometimes it would go on for hours like this. It often happened during actual severe weather events when SkyWarn was activated and 147.360 was being used actively. That of course was not good as it made SkyWarn useless. They usually moved the active SkyWarn ops to one of the backup SkyWarn repeaters so the person at the NWS could clarify severe weather reports if needed.

147.360 is actually located at or near the Red Cross building on Lindbergh.
The 146.850 repeater was known as the Monsanto ARC repeater located in Creve Coeur (Olivette) at or near the Monsanto headquarters at Olive & Lindbergh. I guess that is now the Bayer company.

 

[kruser]

St. Louis Metro Skywarn

St. Louis, Missouri Skywarn program

www.stlskywarn.org

Weather spotters within St. Louis City and County who are amateur radio operators are urged to call WB0AAF on the 146.910 MHz (-)(141.3 Hz) repeater during severe weather to give their reports. By doing so you will insure that the information reaches both the NWS and the Office of Emergency Management. As the National Weather Service wishes to receive reports by county, this program is specific to St. Louis City and County. Other counties in the vicinity maintain their own Skywarn groups.

 

[rjvalenta]

in case anyone wants to hear what i'm referring to, see the attached zip file. it's a shame the repeater has fallen into this state, i remember it being fairly reliable when i was first in to radio... 30 years ago.

thanks for the info.

rjv

 

[rjvalenta]

It may be a digital voice mode, like DMR or Fusion, or even D-star.

Can you post a sample of the noise/signal?

HH

see above, sorry, i should have done a reply to your message.

 

[rjvalenta]

PS - how do we tell RadioReference that it's no longer the Primary for the area? i have 2 Home Patrols that directly import info, i'd like to keep things current...

 

[hkrharry]

"I'm not positive of the actual cause but it sounds to me more like a badly tuned or improper duplexer or cavity filter at the repeater itself where its own transmitter gets back into the receiver and keeps keying it up. Sometimes it would go on for hours like this. It often happened during actual severe weather events when SkyWarn was activated and 147.360 was being used actively. That of course was not good as it made SkyWarn useless. They usually moved the active SkyWarn ops to one of the backup SkyWarn repeaters so the person at the NWS could clarify severe weather reports if needed."

Kruser's description is the best so far as to a cause of the noise...

 

[rjvalenta]

it seems to only be doing it at night…. some kind of wayward propagation and tuning issues combined? anyone know someone at Red Cross to tell them?

"I'm not positive of the actual cause but it sounds to me more like a badly tuned or improper duplexer or cavity filter at the repeater itself where its own transmitter gets back into the receiver and keeps keying it up. Sometimes it would go on for hours like this. It often happened during actual severe weather events when SkyWarn was activated and 147.360 was being used actively. That of course was not good as it made SkyWarn useless. They usually moved the active SkyWarn ops to one of the backup SkyWarn repeaters so the person at the NWS could clarify severe weather reports if needed."

Kruser's description is the best so far as to a cause of the noise...

 

[hkrharry]

PS - how do we tell RadioReference that it's no longer the Primary for the area? i have 2 Home Patrols that directly import info, i'd like to keep things current...

it has been adjusted based on Kruser's information

 

[kruser]

it seems to only be doing it at night…. some kind of wayward propagation and tuning issues combined? anyone know someone at Red Cross to tell them?

It's done it much worse 24x7 in the past. From your samples, it sounds like someone has tried to fix things but who knows when.

W0MDG is the repeaters call sign which is a club shown below from St. Louis, Red Cross - Lindbergh 147.36000 W0MDG Missouri Repeater
See if you can get contact info for the club or the Trustee (K0GOB) listed below and let them know. As long as this repeater has had issues, I'd guess they know however.

An FCC (or maybe ARRL) license search on one of the callsigns below should get you some type of contact info.
The Red Cross may not have anything to do with this repeater officially so keep that in mind and start with the amateur callsigns mentioned first if you wish to attempt to contact someone.


Call Sign Look-Up

W0MDG

Name: Missouri Digital Group
Status: Valid
Type: Club
Club Name: MISSOURI DIGITAL GROUP
Trustee: K0GOB
Expires: 08/12/2028
FCC Record: 0015195332

 

[nd5y]

in case anyone wants to hear what i'm referring to, see the attached zip file.

It's classic audio feedback.
It can be caused by problems with the repeater itself,
another signal mixing with the repeater output creating a mixing product on the repeater's input,
a distant repeater with the same input and output frequencies but reversed,
deliberate interference,
or maybe other reasons.

 

[kruser]

It's classic audio feedback.
It can be caused by problems with the repeater itself,
another signal mixing with the repeater output creating a mixing product on the repeater's input,
a distant repeater with the same input and output frequencies but reversed,
deliberate interference,
or maybe other reasons.

Yep, there's a ton of RF in the area considering that repeater is located near the highest elevation point in the county.
Several multiple antenna LMR towers in very close proximity. I'm not positive but I assume the repeater in question is probably also on one of the LMR towers at the location.
A year or so back, the repeaters TOT was the only thing that would bring it down but as soon as it was keyed up again, the cycle just repeated itself over and over.

 

[kruser]

it seems to only be doing it at night…. some kind of wayward propagation and tuning issues combined? anyone know someone at Red Cross to tell them?

Just wondering if you ever learned more about this?

 

[rjvalenta]

i did not…. but i just got my license back a month ago after 10 years off the air, all i have is a Baofeng, and no idea who’s who to talk to about it… kinda hoped someone would see my post.

Just wondering if you ever learned more about this?