Author Topic: How can I FIND a sensor?  (Read 563 times)

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Offline K4RGD

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How can I FIND a sensor?
« on: September 24, 2021, 08:13:42 AM »
There is a Temp and Humidity sensor showing up on my Acurite Access. It's somewhat accurate (or it was until the batteries started flaking a few weeks back). Now it's hit and miss.

It's showing EXCELLENT signal strength. Fun part is - I don't have this sensor. I have the 5-in-1, which shows up.

I considered the neighbors, but they are too far away to be beaming an excellent signal from a sensor like this.

Is there any way to physically FIND the sensor... foxhunt style? If this is a rogue signal it's VERY accurate and strong and specific. If it's an actual sensor, I'd like to replace the batteries before it goes completely belly-up.

Lived in the house for 14 years now. Had the WX station for about 7. This sensor showed up just a few years back, around the time  we had our HVAC replaced... but the HVAC compny says they don't use or install sensors like these.

Help?

Offline davidmc36

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Re: How can I FIND a sensor?
« Reply #1 on: September 24, 2021, 09:24:06 AM »
Get a "Police" Scanner, maybe a friend has one, tune it to the frequency the sensor should be transmitting on, and remove the antenna. Go walkabout. If you get close enough it should break squelch.

If it is hopping transmission it may be tricky but if you move slowly you should dwell on the area long enough for it to hit the frequency you are tuned to.

Some scanners also have a feature called Close Call that will listen for any signal and alert when it hears something. It sort of needs to be pretty strong for that feature though.

Offline K4RGD

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Re: How can I FIND a sensor?
« Reply #2 on: September 24, 2021, 12:27:30 PM »
Any idea as to the frequency these sensors transmit on?

Offline worachj

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Re: How can I FIND a sensor?
« Reply #3 on: September 24, 2021, 02:11:09 PM »


AcuRite Atlas
KMNSAINT173

Offline vreihen

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Re: How can I FIND a sensor?
« Reply #4 on: September 24, 2021, 03:30:23 PM »
433.920 Mhz, and any ol' 70cm HT should be able to hunt it down fox-hunt style.  They send out 1-2 brief packets per minute, depending on the sensor type.

If you have a USB SDR dongle and a Raspberry Pi in your shack, you can install rtl_sdr and actually read all of the sensors in your airspace.  You may be surprised at how far some of their signals travel.....
WU Gold Stars for everyone! :lol:

Offline davidmc36

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Re: How can I FIND a sensor?
« Reply #5 on: September 24, 2021, 07:45:06 PM »
433. Easy. 20 dollar Baofeng from Amazon if you have no other source handy.

Offline DanInNC

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Re: How can I FIND a sensor?
« Reply #6 on: September 26, 2021, 03:31:24 PM »
I have an extraneous sensor appearing in my access also.  It’s neither the neighbor to the left, or to the right…I take care of their homes when they are away.

That means if anything the signal is from at least two lots away, or just total nonsense.

Maybe one day I’ll know…

Direction finding is a part of the tech level ham test :)