HF Noise? Check Your Ground!
By: John Bruce, KL4O, Delta Junction, Alaska
September 7, 2021
I had been off HF for a couple of years now and feeling deprived. I had pulled my wire antennas down due to high winds and tree movements chaffing the wire. I finally got some help and put a vertical antenna on my second-story roof (metal). I cranked up my HF radio and I had noise from almost anything that had moving parts and plugs in. There was a little bit of something or another on at least one band or another. You know, where you look for distant stations. I could not figure out why my VHF/UHF rig that was totally choked out had no noise problems other than the normal stuff. I had also choked out most of the powered devices going to my HF rig or around it (HF) but was still getting all types of noise from the washing machine, dishwasher, macerator, and even the neighbor’s old generator could be picked up. I had quickly run the LMR400 coax across where the electrical contractors had attached the power lines to my house when they buried the rest of the house power lines.
I thought the fact that the coax was running so close to the power line was the problem. I got a little perturbed and went outside and buried my coaxial line in the ground, and while in the process, I came across my ground which at first looked good to go. When I touched it, I found that the grounding clamp for my ham equipment, which was above the supplemental electrical house-ground, was loose and could be moved easily by hand. BAD GROUND. Someone had loosened my grounding for my HAM station and placed the supplemental house-ground below it and tightened it only. Well, that was good but the HAM ground was not tightened back on and could be easily slid up and down (Not Grounded). The ground wire could easily be pulled out of the clamp. So, I secured it extremely well and sunk the entire grounding setup another two-plus feet beneath the surface. You would have to know where it is to find it as the grounding wires come out of the house beneath the surface in a small conduit. It is a clean install now.
Go back to my HF rig and turn it back on, …. wait for it……it is up with no noise other than regular atmospheric stuff. It is nice, I now have a fully buried set up and it now looks better than most of the rest of the yard (LOL) and with the rain last night you cannot even tell where it is at all. I can also mow and weed eat without hitting that rod, wires, or cabling. (Completed one part of Honey-Do list in the process)
*It appears my HF rig is much more sensitive or just all the right frequencies to pick up all the induced motor noises and such.
My HF rig is an ICOM IC-7610
My VHF/UHF is an Icom IC-9700 and/or a Yaesu FTM-400XDR (in a base set-up)
All my stuff is on UPS and the power supply is also choked on both sides. I have now added more to further reduce noise but the main culprit was the poor/bad grounding without a doubt. I wish I had screen captured the noise on my radio and taken more pictures but you have to know when you get frustrated you just go at it doing manual labor with disgust. Well, I am a happy HAM-er on HF again and loving it!
*Next on the agenda is to get another telephone pole (have 1 already) to put the wire antenna up in a permanent setup.
John KL4O
You must be logged in to post a comment.