Identifying unknown low band freq's in Sonoma County

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DanLP456

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Now that I'm working from home and have my scanner by my side all day, I've taken on a bit of a project. The RR database shows only one low band freq in use by the County of Sonoma, for animal control dispatch. I have noticed that vehicles used by park rangers, the water agency, and county DOT all have low band antennas. County facility operations staff also have radios they use. A license search shows 16 low band freq's licensed to the county that are not identified in the database. I've put those freq's into a folder on my HP-1. Sometime this week I hope to run the scanner all day and record whatever I can pick up and hopefully identify. So far I've heard traffic on 47.9400 that sounds like road construction flaggers. I'll post updates of my search here.
 

kruser

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You may want to search for some of your unknown finds in these low band skip threads below.
A lot of activity is heard across the country coming from your area so something in these threads may help ID some of your finds.


and

 

DanLP456

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Left the scanner running and recording for 20 hours. Picked up loud and clear traffic on 47.9400 CTCSS: 91.5Hz, obviously road construction flaggers. With this freq licensed to the county, I'm guessing safe to say this is a Sonoma County DOT road flagging crew.
 

DanLP456

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Caught two instances of Sheriff's Office dispatch trying to contact Park Rangers on 45.4800 CTCSS 146.2Hz. I suspected that county parks was still using low band for dispatch and the UHF frequencies maybe were for use within individual parks.
 

KC1UA

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My addition to this thread is of no help at all but it brings back memories of being out there at the Coast Guard Training Center in Petaluma back in the late summer/fall/early winter of 1981-82. I had my mom ship my scanner out to me; I think it was one of the Regency Touch Pro models if I'm not mistaken, it was definitely keyboard programmable. At the time it was a thrill to hear activity from another part of the country, only way actually! And there was a LOT of low band back then and I'll never forget some of the comms heard during mudslide season.

Best of luck in your search!
 

gmclam

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Don't just look in the DB for frequencies assigned to Sonoma County. You should also look at statewide and nationwide frequencies.
 

DanLP456

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I've been doing more recording. I'm hearing loud and clear what could be Sonoma Water on 48.4400 CTCSS 146.2 Hz, "caisson 4, operations, starting pump 8" and "caisson 5, this is operations, starting pump 9."
 

DanLP456

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Caught two instances of Sheriff's Office dispatch trying to contact Park Rangers on 45.4800 CTCSS 146.2Hz. I suspected that county parks was still using low band for dispatch and the UHF frequencies maybe were for use within individual parks.
An update to this one. 453.5875 was added to the database recently and is clearly regional parks' countywide frequency, a good add to the scanner! Makes me wonder then why I'm hearing sheriff dispatch come up on 45.4800 looking for rangers :unsure:
 

DanLP456

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FCC Licenses for 48.44 in the State of California
Well looky there! WNGA846 shows the antenna address as being at various caissons all at 9750 Wohler Rd, which is the Sonoma Water Wohler Chlorine Building. WNG847 also shows an antenna at 9750 Wohler. I think we have our answer! And let me ask the audience, the only other freq in these licenses is 47.9400, which all I've ever heard on there is road construction flaggers that I assumed were with county roads, maybe they are Sonoma Water maintenance crews?
 
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inigo88

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Well looky there! WNGA846 shows the antenna address as being at various caissons all at 9750 Wohler Rd, which is the Sonoma Water Wohler Chlorine Building. WNG847 also shows an antenna at 9750 Wohler. I think we have our answer! And let me ask the audience, the only other freq in these licenses is 47.9400, which all I've ever heard on there is road construction flaggers that I assumed were with county roads, maybe they are Sonoma Water maintenance crews?
Counties don’t necessarily categorize their licenses. So it’s very possible that one frequency is water dept and another is roads dept, since they’re both on a generic “Sonoma, County of” license. So 47.94 probably is the regular Roads Dept.
 

DanLP456

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I've been doing more recording. I'm hearing loud and clear what could be Sonoma Water on 48.4400 CTCSS 146.2 Hz, "caisson 4, operations, starting pump 8" and "caisson 5, this is operations, starting pump 9."
Heard similar traffic this weekend on 47.9400 CTCSS 146.2 Hz. "caisson 1, this is operations, starting pump 1" and "caisson 3, this is operations, starting pump 5." But this is the freq where I've only heard road crew flaggers before (with a different PL tone though). This is getting confusing :rolleyes: is it possible the county uses the same freq for different types of operations but keeps them separate with different PL tones? Maybe this reinforces the idea that the road crew guys work for the water agency too? I'll do more recording this week before submitting to the DB.
 

DanLP456

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Today on 48.4400 CTCSS 146.2 Hz, what I believe to be the main freq for Sonoma Water, "operations copies, pump number 9"
 

inigo88

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But this is the freq where I've only heard road crew flaggers before (with a different PL tone though). This is getting confusing :rolleyes: is it possible the county uses the same freq for different types of operations but keeps them separate with different PL tones?
I still don’t think so. The old Kelly Government Radio Systems books have the Sonoma County low band frequencies labeled “Local Government 1” “...2” etc. The local government users are then divided by PL tone. Basically the local government users wouldn’t hear each other with the Rx PL tone on, but they didn’t have enough licensed frequencies to give each agency their own dedicated frequency. If two transmitted at the same time, they would cover each other and neither would get through.

I wasn’t sure if that was still the case based on what you had reported hearing, but now that you’ve confirmed water dept and county roads sharing the same low band frequency with different PL tones I believe this must still be the case.
 
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