Graves Meteor Scatter- It was going so well

[catburglar]

I decided to have a try at meteor scatter detection- using a 3 element yagi based on the S@N design and using a nooelec SDR....following this guide: https://www.popastro.com/main_spa1/meteor/radio-meteor-observing-2020/

The antenna went into the loft on Sunday evening- bearing approx 160 degrees with approx 10 degreees of elevation. All seemed to be working OK- could pick up local FM radio stations so the connections and driver and SDRSharp software must be OK. SpectrumLab was installed and seemed to be getting a few real meteor detections, many short (< 1 second), but other longer and with SNR >15dB according to the log(see the first capture)........Note the caption is incorrect the central frequency is 143048 (not 143028)

So this morning I thought I'd install colourgramme- all went OK, got it to look at my live RMOB log file and everything seemed OK, but when I went back and had a look at SpectrumLab, I've got a spurious signal that I can't track down. I've checked all the connections, unplugged/restarted the PC and it's a permanent feature. The last image shows the difference in signal with the antenna pointing in the usual position (first part) compared to approx due west (second part)....but I need to point south to get the scatter from Graves.....

The system was running for 2 days before this appeared, so don't know if it's something more local that's generating it, although I can't think what it might be. Any clues as to how I should troubleshoot?

 

[Tomatobro]

 welcome to the world of the radio astronomer........

Just as the optical guys suffer from light pollution we have electrical noise interference.

Try moving the frequency up a bit so the meteor ping is still on the screen but the interference is off the top of the scale or narrow the frequency span a little. (or both)

 

[catburglar]

I was surprised I didn’t have any significant interference for a couple of days to see this so suddenly....but as of about 11:30 it seems to have disappeared....not sure what it was, but will see if it reappears.

 

[Geminids]

There is not much rhyme or reason with interference - someone or something turns on a piece of noisy electrical kit, it starts to radiate, it warms up and frequency changes and then switched off (hopefully).    It coud be a TV, USB charger, led lights etc etc -  you will (or may:-)  get to know the different types.  It may be that you are the culprit so look out for kit turned on near your antenna.  There are things that can be done to improve the G4CQM antenna you are using to reduce RFI - location of cables and balun.  A very good start though !