HFU HF Underground

General Category => General Radio Discussion => Topic started by: markolinux on December 22, 2019, 2045 UTC

Title: Weird interference on 31m
Post by: markolinux on December 22, 2019, 2045 UTC

I am listening to (or trying to anyway) Radio Guinea on 9650 kHz, and there's this odd wideband RFI of some sort. I've uploaded a pic... anyone seen anything like this?

I think it's local, but not sure. If anyone else is seeing it, please reply back, so I know it's not local RFI.

73,
Mark Pettifor
Goshen, IN
EN71ao

(https://spacetubes.com/images/31m-interference1.jpg)

Title: Re: Weird interference on 31m
Post by: redhat on December 22, 2019, 2350 UTC

Looks like the same wideband data we've seen recently on 43 meters.

+-RH

Title: Re: Weird interference on 31m
Post by: markolinux on December 23, 2019, 0149 UTC

I also saw a different kind earlier in the day on 31m that was wideband as well. Might be they are related. Will try and post a (smaller  :D ) picture of that too.

Hmm. Been a while since I've posted over here. I need to update my signature!

Title: Re: Weird interference on 31m
Post by: Beerus Maximus on December 23, 2019, 1706 UTC

The #1 generator of wideband HF RFI that I have found around my house are "smart" 12v battery chargers/tenders. Specifically the NOCO Genius brand. I have a couple of these and they destroy HF with ridiculous RFI. Therefore I only use them occasionally to touch up a battery, I never leave them on a battery all of the time.

The 2nd worst generator of local RFI is undercabinet 12vdc LED strip lighting. The tiny switching power supplies they use are complete garbage.

Title: Re: Weird interference on 31m
Post by: ChrisSmolinski on December 23, 2019, 2131 UTC

Don't forget about newer KitchenAid mixers with PWM DC motors. I understand some are reporting RFI from new home HVAC systems with similar blower motors.

(https://i.imgur.com/pNfunsL.jpg)