Excellent advice re: attenuator. Once while using MFJ 856 (135 mHz RX & 3 element), it got completely overloaded within few hundred feet of source. While being in close and overloaded, the field stre
In October 2017 I started to observe some spitting type broadband RFI noise spikes. Within a week or so noticed that when outside temperature cooled in evening the noise spikes would become constant.
Your current situation provides a unique opportunity. You'll be way ahead of the game IF you can somehow get the installer (or better yet: a supervisor) to look at a spectral display of the before vs
Charles raises a great topic - one that must have simple answer - but which has confounded me for a long time. Perhaps we should start a new topic subject line. Alan, K0AV ___________________________
I know that we can minimize RFI / noise pickup by minimizing the common mode currents on our feed lines. And, that we want the choke to reduce common mode current to near zero. I have seen **differen
Hi Karin ~ Ill start by saying I dont have any experience with grow light RFI but I am interested in learning what progress you make in the DFing process. I too have the National RF setup. Hoping you
Just to keep this thread going . . . In addition to all the great ideas already posted, you might also consider: (1) Validate the directivity of the DF loop you are using. Generate a small signal on
Ed ~ beam, I RFI sniffed around another antenna feed line (coax) from a separate 40 meter beam. I was astounded to see how much hash was present on the 40 meter coax. I don't know exactly what was ge
Our city (Colorado Springs) is installing LED street lights with some new type of controllers. I am not sure, but I believe these are made by a company named Lumenistic (of Boulder, Colorado). Here i
Kenny ~ This summer we had 5 of that type of Utilitech LED's put into our kitchen. The kitchen is probably less than 100 feet from my antennas. Sorry - but I can't find the model number - but they ar
For what it's worth . . . NK7Z posted a panadapter image of a defective lightning arrestor. It was 2000 feet from my antennas. I watched them go up and replace it. Here's the link: infrastructure <ht
In 2019 K3LR presented such a test at the Dayton Contest University. Tim describes it @ 15:30 into the presentation. Here is the YouTube link: https://www.youtube.com/watch?v=wd5B5qPHI_U The relevant
In the past few days I've started using a Flag Loop antenna (designed by WD8DSB). I supplement it by also using a National RF HF-DF bidirectional loop. The patterns on both have been confirmed by usi
Mike ~ I don't know how well the Flag Loop hears compared to a magnetic loop. But, both are usually used with preamps and attenuators - so that you can adjust the noise levels down to where the S-met
Dave ~ Adding a spectrum analyzer should be interesting. Getting it all configured for easy use in the field is the next logical step. I hope it is broadbanded. While the SWR measured 1.1 to 1 from 1
Pretty interesting Don. Thanks. You have quickly upped your game. Moving way beyond just listening to scratchy noise on a single channel of a VHF or SW receiver. I noticed that you are wearing a safe
Have you been watching when it actually first starts up? - I would guess there is some drifting occurring before the frequency stabilizes. - But, the most important thing to know at this point is whe
I second Chris' suggestion to use the portable flag loop with preamp. Within the past 4 months, I have used one about 5 times to pinpoint noise sources. Either build one from WD8DSB's article in Marc
My wife suggested that I get a tinfoil hat -- and perhaps all of us on the RFI list should get one. https://www.snarkgifts.com/products/tin-foil-hat-for-people?variant=30912742588451¤cy=USD&utm