Better Ethernet Cable

RBOOM & Infrasound
#1

Besides having my Boom and Shake in the poorest place there is (a lot of traffic of all kinds, cars, trucks, planes, trains, you name it) it looks like I also have problem with a lot of RF that I can’t seem to get away from. i tried a heavy steel electrical cover and aluminum foil and it didn’t help. According to the install guide, it says if all else fails, try a better quality Ethernet cable. The question is, which Ethernet cable would provide better shielding than the one that came with the Boom? My ID is RBED8 for the Boom and R6458 for the Shake if you want to take a look.

“Generally, if the spurious tones exist, move the system away from any generators (wireless phones, cell phones, modems, microwave ovens, …). If that does not work, enclose the system in a metal box. If that still does not help, replace the Ethernet cable with a higher quality one.”

https://manual.raspberryshake.org/boom.html

#2

Hello harry,

Yes, it is quite a common situation, trying to find the best spot for one of our Shakes being in a ‘noisy’ and ‘perturbed’ environment.

Usually our products are shipped with a CAT5E LAN cable, and the recommendation is (if this cable picks too much interference, like in your case) to switch it with a CAT6 LAN cable. However, if the RF interference is still present, then it may be necessary to shield everything, from the Shake itself to the data transmission cable.

However, I took a look at your RBOOM infrasound channel stream and, at least in the last 24 hours, I could not see particular or relevant interferences. Could you please post an example of what you are seeing so that we may analyse the situation with an actual chart?

Thank you.

#3

Thanks for the info. I’ll try the CAT6 and let you know what happens. Here are a couple of examples of what looks to me as RF interference. The first one from the Boom (RBED8) shows a red line near the top of the spectrogram and the second from the Shake (R6458) shows the red lines near the top and middle of the spectrogram.

RBED8_HDF_AM_00.sac (24.1 KB)

#4

This is just the Boom file. The RBoom is relatively insensitive to electrical interference.

In any case, the display you are looking at is the result of many settings that we don’t have by looking at the SAC file. It would be better if you made a screen shot of what you consider suspicious and attach that as a PNG or JPEG.

Looking at the RS on line, there sure is a lot of “activity”! If you are talking about the various horizontal bands at 10-20-30 Hz, its quite possible that these are the result of heavy machinery, perhaps quite some distance from you.

I can suggest you put the RS on a big soft pillow and see if the 20 Hz stuff stays the same, or drops way down in amplitude. That will tell you if it is mechanical or electrical :wink:

Ken

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#5

I agree with what @kpjamro stated.

The high-counts spikes that I can see on the Shake (R6458) do not seem to be electrical, or RF interference, in origin, but please let us know the results of your tests on this.

#6

With your help it looks like I was able to isolate the problem which is that the RS is to close to a PC and must be picking up the fan noise. I noticed that late at night when the traffic dies down, the red lines in first image are very noticeable and after I shut down the PC for the night, they go away except for the red line that shows in the top in the second image. So, I just need to find a better place for the RS. I greatly appreciate the help.

R6458-1
R6458-2

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#7

Thank you for reporting back harry, I’m sure this will be useful to other present and future Shakers if they find themselves in a similar situation.

I’m sure that you will be able to find a proper (or, as it was my case, the best possible compromise) location easily!

I and the community are here for this too!

#8

Fans make great infrasound sources. My attic fan comes in loud and clear 50 meters away. On some days I can display wind turbines that are 100 km away …

And - I think - I recorded a drone that the police may be using. It is too weak to show up on RShake but it showed on RB (~5 km distance). I assume it is a drone, due to rapid changes in speed that I have never seen on a full-sized helicopter.

Ken
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