Hello Radio!!: 20 Meter RFI problem solved, 160-6M antenna failure.

Thursday, June 10, 2021

20 Meter RFI problem solved, 160-6M antenna failure.

20 Meter RFI problem solved

Since I moved into my shack above the garage, I have had RFI issues with my hard wired smoke detectors on 20 meters.

Well, recently I put up a new OCF dipole antenna that was suppose to give me 160-6 meters. While I was checking it out, I gradually increased the power on all bands checking for bad things. When I got to 20 meters, I was able to increase the power to 100% (70 Watts) without the smoke detectors going off. My first thought was that the new antenna did a better job of containing the RFI issue. I don't think this is correct.

Unfortunately, or serendipitously, the 160-6 meter antenna broke (see below) and I put my old 80-6 meter OCF back up. I again slowly increased power on 20 meters waiting for the smoke detectors to go off, but again, they didn't.

What had changed? Then I realized that since my initial setup back in Oct of 2019, I had purchased three metal shelves and set them up against one of the walls in the storage area. The antenna coax is behind the shelves. I believe the shelves are shielding the smoke detector from my antenna wire. Hey, that's my story and I am sticking to it hi hi. Bottom line, I haven't had any problems since.

You can see my antenna coax on the floor behind the shelves.

Antenna Failure

Well my 160-6M OCF did not hold up to the winds I get here. It broke where I thought it would, at the inductor. The wires are soldered into the terminal lugs, not crimped, and there is no strain relief on the terminals. Depending on a soldered joint for mechanical connection is not a good idea. For one thing, solder will deteriorate when exposed to the weather and for another, a cold solder joint could also compromise the connection.

Well it looks like I have another antenna repair project to look forward to, oh joy!

I am going to try and add some strain relief to these connections.