SM7UZY

Hunting the interference!



Mars 2019


I don’t have interference, but I have it! When I moved to my new location I was happy then I notes that I didn't have a lot of interference. More or less nothing! I had ground noice, but not interference..

My antenna is a good TX antenna, but in receive, it’s a little bit worse. Not bad, but not good as I have some ground noice. I live really close to a train track and there is not many trains, but there is high power lines. I didn’t notes the interference from the power lines as it was outside the ham bands, and it’s only on some few frequency when I checked the whole HF band. So it’s not a problem! The ground noice... yheaaa... If that could be lower I would be happy.

I can’t cut the train power.. of course, so I thinking to have a receive antenna as this antenna works very well on TX.

But I noticed some other interference that I wonder about, so I went out on YouTube and looked for HF interference to see if others have the same interference as I, and there is many good films.


Lets the hunt begin!



I cut the power to the house, took a battery to the radio and was happy that a loot of the interference went away... yesss... noooo... Nothing!
So is all this crap from my neighborhood?

I come a cross a video about network interference and went to 14.213 and 14.273, and yes... there it was. But this is not my network! I don’t have power.. And I have rack switchers that is really good, both single and double shilled TP cables and so on. I put a loot into my network.

This is without any power in my house. I use PREAMP1 to get it more visible and you see three lines... that’s some of my neighbor using a plastic box somewhere.


I started to put the power back. I know that my kitchen lamp generate some interference if i place a HT side by side on the lamp, but nothing on the radios.

After some more investigation I notes a small interference that I caused. My network... on other frequency? You can see a small one on the picture above, so my neighbor generate the same interference. But no... it’s not my network, it’s one of my main screen!

And if you look close, I generate some noice as well. The capture screen showing more noice than above. So I will cut the power again and put on one device at the time.


I know that one of my main monitor generate some interference. I can live with that.. No one need to use that screen if I am on HF.

One thing that tricked me was all the digital signals all over the place that I thought was interference. After monitor the signals I noticed that is actually signals, not interference. So yheaa.. there went a loot of “interference” away.

So, the only thing is my main monitor that generate a small amount of interference (that I know about and affects some ham bands), all the other is from my neighborhood. The first step is to see if I can lower the ground noice that i generate, and then play with a receiving antenna.



I don’t have any interference on 2m, except for the thing you see on the screen.

Sometimes i also have the “fish pattern” you see, but that don’t interfere the sound, only the waterfall, except if its really heavy on SSB. I think this is from the train power line.


One thing I know about the train power line is that in some spots in the house i got really nasty interference on all the HTs. Both on HF, VHF and UHF. So I know that I have problems with the power lines, but only on the HT... I think!


Well.. I am not finished with this... I will continue.