Mystery sound on 452.325

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wbswetnam

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I have heard this sound for months on 452.325 MHz. It sounds like a control channel, but of what? Does anybody know? (access the Archive.org page, then select 'wave' on the lower right-hand side): Mystery digital sound
 

nd5y

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Where was it heard?
Did you look up FCC licenses for that frequency in that area?
It's not a control channel. It's probably SCADA or something.
 

wbswetnam

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Russellville, Arkansas. I did a frequency search, but none of the three results are anywhere near to where I live. The nearest is 100 miles away in Washington County. NXDN?
 

LD723

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I hear the exact same thing on 900 mhz in my area and never knew what that is and it sounds 100% the same as yours
 

217

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Do you live near a water tower? There is an expired license in Russellville that used 452.325. It may still be in use.
 

ltginrage

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That shoulds like DMR. I got that same sound when I programmed a frequency that said it was conventional and was later updated to a DMR Frequency.
 

wbswetnam

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Entergy (my electric company) has a "smart meter" within 25' of the antenna. I wonder if it's a data link from the meter?
 

kruser

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Likely Not - most of those are 902 MHz and 2.4 GHz
That and smart meters do not transmit continuously.

Smart meters often send packets of data to a master receiver mounted in an area that gets signals from several meters. That receiver then re-transmits the data back to the utility company. I think some of them use store and forward where they don't transmit the data they received until their buffer is nearly full. I have one here that receives the smart meters in the 902 - 928 ISM band and sends the collected data back to the power company over a cell phone data connection.
 
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RadioDitch

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Just by the frequency, I'm 98% sure its OFDM utilities data. Not a smart meter, but possibly either UHF PLCC or a continuous reporting flow meter. To me it sounds like FLASH-OFDM, which doesn't make sense since Qualcomm ended that service...allegedly.

The closest sounding trunking signal to that would be NXDN-96, but the interval is wrong.
 
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Australia4001

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Sounds like a dmr control channel , Not simplex dmr ,

to hear the system correctly you need all the other site frequencies and then run LCN finder to trunk track ,

have you set the scanner to digital only mode for that entry?
 

RadioDitch

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Sounds like a dmr control channel , Not simplex dmr ,

to hear the system correctly you need all the other site frequencies and then run LCN finder to trunk track ,

have you set the scanner to digital only mode for that entry?
A Uniden scanner with the appropriate DMR upgrade, which the OP notes he has, would be able to decode the control channel data to display a System ID. The pitch and interval also sounds wrong to be DMR on what's a really clear audio file. Sounds more like utilities data.
 

LD723

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Yeah it's clearly not dmr I have used dsdplus through the usual tcp input and not a single decode on my end for the same signal. Like I said before for me it's on 900mhz and it's the same exact signal this guy is receiving and it's pretty strong I will link in audio file for comparison soon.
 
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