KX0R on SOTA W0C/SP-111 vs LED lamps QRM

I left work at 18h07 local (17h07 utc) and after phoning my xyl and getting the green card from her, I headed to my house in the village to try to work some SOTA DX from North America.

As soon as I got into the shack, I saw my neighbour had his backyard LED lamps ON,

which inevitably means a constant S8 QRM on my receptor:

My neighbour is an ex-work colleague and I keep a friendly relationship with him, so I sent him a begging message and after a few minutes he saw it and switched the LED lamps OFF. Thanks very much buddy!
Here you can see the immediate effect on my receptor:

There were 3 different activations spotted on 20m CW at about the same time:

@AE5KA was not copied at all,
I didn’t go to check for N6MKW because I was sure I wouldn’t copy him, as he was on SSB and on a W6 SOTA. Too far away for me.
@WS0TA was not copied at all,
@KX0R was weak with some rapid QSB, but again he made it and we could complete the QSO. After our QSO, I lingered on the frequency and George’s signal improved to 449 for a short while.
I was using my TH5-DX tribander yagi up 15m above the ground and an output power of about 800 watts from my TS-940S plus TL-922.
It was a joy and a pleasure to QSO with you again, George. It was our 79th SOTA QSO.
Best 73,




This was indeed a surprise to hear you so easily on 20M CW from W0C/SP-111. It was even more incredible to be activating above 3000M on the day before Winter Solstice. The temperature was about 10 C, with warm sun, although I hiked most of the way up in light snow.

You can see the antenna and pole near the summit in the photo above. Can you believe the sunny scene?

I used the usual rig:

KX2 at 10W
20M inverted-L wire at about 5M
Homebrew high-Z tuner

I’m amazed that you could hear me yet another time. Please thank your neighbor for helping us by switching off his noisy LED system!

What is even more amazing is that 2 minutes before we made our contact, ZL1BYZ called me and also made contact on the same frequency, with about the same signal levels! He also has made numerous SOTA contacts with me and other SOTA activators.

This is not the first time that I have contacted EU and ZL in the same SOTA activation, but it seems magical to have these contacts right together.

Also several times recently I have been hearing my own signal echoes, actually my own signals coming all the way around the earth via the long path, while calling CQ or in QSO. Even more often, I hear these echoes on QRO chasers - they are very easy to hear with the KX2. This is on 20M and 17M CW - but the bands are certainly not dead, and it is always amazing to hear these echoes and to realize what they mean. This is not an artifact of the radio - the echoes come and go and change with the propagation, as well as which station is being heard.

At first I think these signals are QRM from another station on my frequency, but when I stop, they stop, and when I send, there they are, audible for just a fraction of a second after my signal.

Many of our Colorado SOTA peaks are in somewhat undeveloped areas, so noise levels are often very low. This makes it possible to hear echoes and weak signals that I can’t hear at home.

Thanks again Guru - Happy Holidays - 73



Amazing SOTA day you had, George!
Not only for the excellent WX but also for the DX worked from both ends to the other of the World at about the same time.
Except once on 12m, I’ve never heard again the echoes of multi path signals comming in during one of my SOTA activations. Of course I neither activate as often as you do nor as high above sea level as you do. I remember hearing those echoes on 20m several times with my base station and it was mainly with stations from UA0, JA, KL7, VE7, W7 but that was quite long time ago, when I had more time to be on the bands.
Please, keep activating and doing as good job as you’ve always been doing so far.
I hope I’ll keep chasing you and many other Northamerican activators as often as possible.
Best 73,


It was common during our SOTA 12m challenge. The best (worst because I could not resolve the call) was myself and G4OBK on 12m. We were only 320kms apart but a single dit from me had about 5-8 echoes and Phil’s call became a total jumble of dits and dahs. There were lots of signals on 12m but I only worked 2 QSOs due to the problems of echoes from multipath round the world signals.