Different type of trace

I recently moved my RS4D from the garage to the back yard to eliminate some of the road noise. It seems to have helped but now i see a periodic (1 cycle?) trace jump. Has anyone see anything similar and know the cause? This never occurred when it was inside the garage Jim / AM.R907E

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There have been several threads about exactly what these might be. Interesting that you didn’t see them before moving the device.

A good experiment, for someone that has more than one shake, would be to place a pair fairly close together and see if recorded spikes occur at the same time on both. Unfortunately, I don’t have the funds to buy another.

Mine is in a (metal) pole-barn so somewhat protected from random radio signals, and has a dedicated UPS which includes transient filters.

Another interesting thing is that my device is a Shake-Boom. These spikes only occur on the seismometer channel, nothing at all on the infrasound, so it seems to be being picked up by the geophone, not from power glitches on the R-Pi. So another interesting test would be for someone with a RS3D to see if there are coincident spikes on all channels, or at least more than one.

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I said that the spikes on the EHZ (geophone) channel didn’t appear on the HDF (infrasound) channel … so looking at it just after saying that, one of the “spikes” appears on both - I think this one is a bit different, because it is not a clean trace like the others:

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Hello Jim, welcome to our community!

As Philip has already stated, many different threads (if you search for “spikes” in our forum you will easily find them) have approached this ussue of strange repeating spurious signals such as the ones that you have noticed.

It is interesting that they have appeared after you moved the Shake to another location, as they can usually be connected to some kind of external interference. Have you tried to move it to other areas in your house/property, to see if they continue to appear, if they disappear, or if they decrease in amplitude?

This could provide you with insight on the RF environment around you, and maybe help you in finding a good compromise between low noise and absence of spikes. Many of them appear like this one, with a strong activity pulse only in the lower frequencies, reaching maybe 12-15 Hz.

Hi Philip+StormChaser,
Thanks for your replies and suggestions. I did take a look at some others in the area like AM.R2EF4, AM.RDD49, and AM.RAAE6 (all within a ~2 miles) and theirs do not show the same blip. So, I am concluding this is something very local, possibly some source within a few hundred feet. My first thought were those ultrasonic gopher repellent devices, but the mfgr states the frequency of the sound is every 30 seconds for 2 seconds duration… not a match.

So, per your suggestions, my next step is to move it closer to the house and see what happens.

Thanks again… jim

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No problem at all Jim, hopefully you will manage to find a location that is good for both noise and absence of these spikes!

If you do find any sort of useful information, please to mention it here. There are a few people who are probably interested!

Philip

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