A nice Weather map from down under


This is what I used to get with a home made QFH antenna, a LNA4ALL pre-amp and a rtl-sdr on SDR# and Wxtoimg.

I’m not able to get anywhere near this quality via Satnogs nor have I seen anything like it from other observations.

I think my problem may be related to the huge amount of EMI emanating from my 3 Raspberry Pis. S8 on a nearby FT-817 on 2m band.

I would be happy if someone could send me a link to an observation of this quality please. I would be even happier if someone has found a solution to the Raspberry Pi noise problem.
I have already taken the usual basic steps, grounding the metal case of the RPis and SDRs, Clamp on toroids on all power leads. I’m using 5v buck regulators which produce no noise by themselves on VHF or UHF.

With so many Ground stations out there someone must have experienced similar problems.

Over to you and thanks for taking the time to respond.

73 Bob vk2byf


I don’t think the tool used for NOAA processing can do the false colour on Satnogs yet.

Here’s one from my station:

There is also this one from my station : https://network.satnogs.org/observations/785194/ which I happily recorded the IQ (you’ll probably have to convert short to complex) http://satnogs-iq.s3-ap-southeast-2.amazonaws.com/785194.raw so you could probably try playing that back through the software your using.

I posted some details here https://photos.google.com/share/AF1QipNP-yzE4BqSc3Wxyl_DLP23zkTFfZhMEAYXvOE2d7vGSS4CGR7YxoMXmA20EzqByw?key=cENPSEZCMGRmV0JjUW5kbGVGTE5EOENCV3Z1M1BR on the setup I built, but if you want to know specifics just let me know.

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Thanks Michael for your information
You have certainly made a big effort in your industrial strength installation.
I suspect you may be involved in the Electrical Trade. Hi Hi
With your RPis in shielded boxes and your Bias-Tee also in metal boxes and then the entire setup in another metal box, do you still suffer from wideband noise on the 2m band which I have worked out comes mainly from the RPi3B+ and rtl-sdrs. Strangely my old RPi3 with green fake rtl-sdr v3 does not make any noise now that I have sorted out the earthing of the RPi and rtl-sdr cases.

I’m surprised how good a picture you are getting. Looks like you are in a clear elevated QTH. I have mountains to the West and North and big trees all around me so my horizon starts at 10-20 degrees.

Are you using any Low Noise Amplification. I think, Yes hence the Bias-Tees. I’m using LNA4ALL and I suspect one of them may be faulty or oscillating. Time to bring down the antenna for a look see. I’m afraid my antenna farm is getting a bit out of hand. 24 last count.
73, Bob vk2byf

Not so much in the electrical trade, but I did work with a bunch of them for a couple of years. I needed a robust setup as I’m about 23 hours drive from the station. I do have a bit of an obstruction due to a hill in the west.

I’m using the Minikits LNAs though I did test the LNA4ALL and it worked equally as well. I do know the LNA4ALL can have ESD issues, so there is a mod to put a diode in place to prevent voltage build up - http://lna4all.blogspot.com/.

I haven’t had much issues with wide band noise, I was very thorough in my build to test all the components as I wouldn’t have fast access to supplies if I needed to replace parts out during the install. My biggest concern was the PSU but it turned out to be fairly good. The only issue I had was the LED fluro tube replacements next door created lots of noise.

I’m not sure why you’d be getting noise from the RTL-SDRs or Pi, I tested for the 3 and the 3B+ with genuine RTL-SDRs. We did have an issue with another install where the PSU for the Pi was creating lots of noise and replacing that out helped significantly.

Hope you find the issue!