Omega-TI
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I'm stumped. Anyone have an idea of what this could be?
Does anyone have a clue what this is?
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I'm guessing it might be RFI caused by something in your house or neighbor's but I could be wrong. Sounds like a sign flashing on and off or an aquarium heater. It's pretty narrow band and I would expect RFI to be wider but maybe not. When I used to track down powerline RFI when I worked for a large electric utility, we found all kinds of stuff and they all sound different. I remember an aquarium heater sounding like that though and it was coming from half a block away. Electric blankets sounded more like a heartbeat, thump, thump....thump, thump.
Omega-TI
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This time I monitored in RAW format and dialed out some of the static and processed the sound a little. Whatever it is, it sounds digital.
Well it'd be more helpful if you would give us the basic info. Where are you located exactly? Are you talking about the signal on the left or the right side of the screen (where the frequency cursor is located) -- give us the exact frequency.
FWIW, the signal on the left looks like a paging frequency.
FWIW, the signal on the left looks like a paging frequency.
Omega-TI
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The exact frequency is shown on the display, which is 155.125. My QTH is in southern Lewis County near Winlock.
It's the frequency on the right-hand side.
mmckenna
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155.125 is not a legit assignable frequency. It's probably 155.1225MHz.
Cowlitz County Fire has an NXDN repeater on that frequency you may be hearing. It may be beaconing
City of Kent has an NXDN trunked system on that frequency:
Might be a control channel for a Type D system.
Cowlitz County Fire has an NXDN repeater on that frequency you may be hearing. It may be beaconing
City of Kent has an NXDN trunked system on that frequency:
Might be a control channel for a Type D system.
It's currently licensed in Anchorage at an ERP of 500w.
Might be a bit far from the OP, I think he's up in the PNW somewhere.
mmckenna
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I don't doubt it. In Washington state, there's nothing licensed on that frequency. The public safety pool only shows 155.1225 and 155.130.
One of the two NXDN sites on that frequency near him are likely the source.
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reminds me of when I ran across the LO of a pager that had a battery save feature.
It's not from City of Kent -- their repeater isn't THAT strong.
Or if you have an Android phone and you happen to tune 13560khz on your QRP rig...
Omega-TI
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After zooming in and doing some fine tuning, I found that you are correct, so it probably is the Cowlitz County Fire NXDN repeater as it's within my listening range. I'm just getting back into radio after a twenty year break, so this NXDN stuff is all new to me. My RTL-SDR is not configured for it, (don't know how to do that) and I've not paid for the upgrade for my SDS100.
Now I did get a data burst, so some of you guys might might recognize the pattern.
mmckenna
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It seems too closely spaced for site roaming beacons, but I could be wrong.
I don't have a Type D system to compare it to, so I don't know if it's some sort of home channel marker.
I don't have a Type D system to compare it to, so I don't know if it's some sort of home channel marker.
Hehe that's not NXDN. His B/W is 5khz wide and that's not even 1khz. It's probably just telemetry from some random device. Also I don't trust RTL-SDRs and their frequency accuracy. If he had an Airspy SDR then it would be more accurate.
there is quite a few of them loitering over here
Ditto. Got a few Type Ds to compare to in Philly area. Spacing is definitely further apart
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