Are some Boulder police channels encrypted?

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K9LOL

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I added a variety of Boulder police channels to my new Yaesu FT-1900R, but a notice a few of them are completely drowned out by an apparent digital signal that sounds like a buzz saw. That includes Black, Purple, Violet, and Emergency Squad. Is this really the case, or is there something else going on?
 

mass-man

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Big D, little a, double l, a s
That sounds like P25 digital. But the RR DB shows nothing of the sort. Anyone up there know what's going on???

In addition to just wondering, I am headed up that way in a few weeks for work and bringing my scanner....
 

chris_a_rodgers

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Sounds like you're getting interference from a nearby source. If you don't already you should have the PL tones for those frequencies programmed. None of those channels have P25 associated with them. I listen to them all the time.
 

Steve2003

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I would double check your frequencies. That sounds exactly like what I hear when searching through the taxi cab frequency range. I heard the exact same audio on the following:
152.33
152.36
152.39
152.42

Also, here is a good place to check those mysterious sounds
http://www.kb9ukd.com/digital/
 

K9LOL

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I double-checked all the PL tones and they're set correctly. It just seems weird that those same channels seem to get similar interference all over town, but no one else is mentioning it.

Steve, I double-checked the frequencies and they're correct. Sounds like something is just stomping all over that band, although Chris says he can monitor it fine.
 
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kjk681

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I live in Broomfield and do not hear what you do. I have a commercial radio that is less susceptible to interference. However, I have noticed that Blue does not see to get out as well as it used to around my house. Not sure if the output power has dropped or if they may have moved it to another one of their sites to improve coverage within the city.
 

ecanderson

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I'm in Longmont, and also do not hear that sort of interference. Wonder if you're physically close to another strong RF source? Are you stationary or mobile?
 

towersites

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I was up on Eldo Mountain were that nasty interferance / mixing is coming from.
They are using low dollar amps with Kenwood repeaters. No filters that I could see
My guess all four transmitters have there own antennas which is not good. They get
into my repeater on Lookout Mountain. I have also heard them come up on Red 1. I would
say there is a lot of mixing going on. One day the microwave link went down and the interferance
went away. I could tell right away when it was back up.
 

Spitfire8520

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I would double check your frequencies. That sounds exactly like what I hear when searching through the taxi cab frequency range. I heard the exact same audio on the following:
152.33
152.36
152.39
152.42

Also, here is a good place to check those mysterious sounds
Digital*Modes*Samples
I get the same audio from 152.33 and 152.42 from the City of Boulder area, but it does not show up on any public safety frequency. I'm wondering if there's some kind of transmitter near you just washing out your signal in the 155 MHz range or if you have it programmed correctly because Black doesn't usually get used all that often and it sounds sort of like someone's routine dispatch (once you get past the grinding noise).
 

K9LOL

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I was up on Eldo Mountain were that nasty interferance / mixing is coming from.
They are using low dollar amps with Kenwood repeaters. No filters that I could see
My guess all four transmitters have there own antennas which is not good. They get
into my repeater on Lookout Mountain. I have also heard them come up on Red 1. I would
say there is a lot of mixing going on. One day the microwave link went down and the interferance
went away. I could tell right away when it was back up.
I get this noise primarily in South Boulder, so that makes sense. Foo. Looks like I'll just have to keep those channels out of my scanning lineup.
 

Thayne

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A few calls to the FCC would probably make Yellow cab spend a little $$ and fix it---but then again it looks like those UBER rides might drive them out of business:p
 

soundchaser

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I get this noise primarily in South Boulder, so that makes sense. Foo. Looks like I'll just have to keep those channels out of my scanning lineup.
I get the interference when traveling 36 from Boulder to about west Broomfield.

I also get the interference on the opposite side of Eldorado, just east of Wondervu. I'm usually mobile listening to rail frequencies in that area and the interference just bleeds into every channel I have programmed. Rail doesn't use PL tones (not that it would help much if they did). Very annoying.:mad:

Based on the locations, it does seem to originate on Eldorado Mountain.
 

K9LOL

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I have filed a notice with the FCC. I'll let you know if I hear anything. It would probably help if others did the same.
 

ecanderson

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Given that it is a public safety agency that is being interfered with, it's also possible to call directly to make this sort of complaint, though it's nominally for deliberate jamming: 1-888-225-5322
 

dw2872

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Also, it is probably better that a member of the communications staff at a public safety agency be the one doing the calling to that number.

I am fairly certain that they are not seeing the interference that we are though.
 

Spitfire8520

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I am fairly certain that they are not seeing the interference that we are though.
I'm thinking the same thing as I have been on 36 quite a bit with my Pro-106 scanning 90% of the Boulder County frequencies (BPD Data, Black, BES, and anything else public safety) and don't recall experiencing the interference that others seem to be seeing (granted I'm using the 800 MHz antenna). I actually don't have any of the tone squelches (PL or DCS) programmed since I rarely get any interference.
 

K9LOL

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I got a letter in the mail from the FCC acknowledging my complaint. Not sure if anything happens now, but at least I tried

I'm curious if anyone knows whether I should turn on tone squelch or not for the police frequencies? I gather if I have it enabled but they're not using it for transmit (only receive), that I won't get any transmissions. Or maybe I'm misunderstanding. ;)
 

Spitfire8520

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I think it really depends on how the system is setup for transmitting and receiving. My impression is that most of the repeaters for Boulder County are activated only when it receives the correct tone squelch in order to limit interference from things like skip. This would mean that all radios are programmed to transmit using only the correct tone squelches if they are used for repeater operations.

The other way of handling repeaters is to have a carrier signal activated repeater, which would allow for any radio on that frequency to transmit regardless of tone squelch. Like noted in the above, this would allow for interference to activate the repeater at any given time and is a less likely configuration for repeater use.

I've drawn this conclusion from the previously mentioned fact that I have been scanning Boulder County without any tone squelches and have not noticed any transmissions, sans repeater CWIDs that use carrier squelch only, that have used a different tone as the ones listed in the database. The only difference I have experienced between using one and not using one is that my scanner seems to open up a little faster than with a tone squelch and may hold onto very weak signals a little longer, otherwise it doesn't really change much. I generally favor not monitoring with a tone squelch unless I run into considerable interference from another user on the same frequency (not likely in Colorado). If you don't like your radio locking on a frequency because the repeater is identifying itself, then using the tone squelch is not a bad idea.
 

K9LOL

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Thanks for that. I actually just tested it now using Green, and it appears that Tone Squelch blocks receiving (and, as you noted, slows scanning). I was hoping turning it on would help block the interference I'm getting, but maybe not.

Correction: I had the wrong tone. :p Tone squelch does work on green.

I guess I'd have to test them individually, which is kind of a hassle with this radio (Yaesu FT-1900R).
 
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