I would just like to say sorry to the Activators i have given poor reports to, struggled with them or not come back to over the last couple of weeks. I only try to make contact if i can hear them at some point.
I am suffering with QRM between about 7.110-7.125 and it’s peak is around 7.118, which most UK and EU SOTA Activators use.
Hello Mick, I suggest, if you can, is borrow a battery from a car and then when the noise is present put the radio on the battery supply and turn off your 240v main supply at the consumer unit/fuse box. If the noise goes then it is something in your home generating the noise. If it remains you know it is not you and then you have tedious job of using a scanner or similar portable device to track the source. Where are your antenna situated?
You could make a noise canceling antenna. One small antenna to pick up the noise, one antenna to use for signal RX and TX and a phasing box so you can mix the noise with the signal 180degs out of phase and cancel it out. There are plenty of plans out there on ‘teh intarwebs’.
I have this problem, too, Mick, a general big increase in background noise with discrete bands of very strong noise, one of them between 7115 and 7125. This comes from my neighbours plasma TV. His house side wall is the boundary to the side passage of my house, I can put the rubber duck in the FT817 and walk down the passage and get a terrific noise peak where the corner of his room with the TV is. Fortunately he watches little TV other than the weekend sports programs so the rest of the time the noise is about four S-points weaker, though still annoying. I find the 817 great for locating noise sources!
I believe it is mainly the older plasma TVs that are troublesome so I have been hoping that it would eventually be replaced with something more modern, but he now intends to move.
I think it must be a neighbours TV or something similar as the noise has gone this morning i am sure it will be back as soon as the offending item is switched back on.
Hope your new neighbour doesn’t cause you the same problems if your current one moves.
Good news Mick. My QRN problem is on 14.285. The source is a switched mode PSU on a eletric music organ she, my neighbour, bought from China. She likes to practice every now and then in the afternoon (sob!). I am hoping she loses interest, sells it, or the PSU self destructs.
Hi Chris hope you are well, not heard you on the radio for a while.
Thanks very much for the offer to call round with the 817 but I am now sure the noise isn’t coming from my QTH because is stopped this morning. Even if I located the source I don’t think there will be anything I could do about it
Thanks again for the offer and hope to hear you on a summit or maybe even join you from one soon.
Just managed my first chase for the best part of a fortnight. QRM/QRN has been running at S9 on 5MHz, S9+ on 7MHz and S8 on 10MHz. I managed to work Juerg DL/HB9BIN/P on 10MHz CW as he was S9+.
In reply to G4OIG:
I suffer from S9 mush at the home QTH, but I haven’t noticed a particular pattern in timing, I just make the most of the quiet periods. I have done the “power down the house” experiment, so I know that it isn’t anything of mine.
When I started in Amateur Radio, the problem was almost exclusively in the other direction - band 1 TVs, early solid state HIFI etc very susceptible to RFI.
I wonder if we’ll ever turn the corner and see unwanted emissions falling? Dream on!
In reply to M0MDA:
That qrn sounds a bit like plasma tv it rises and falls in strength every few kHz, unfortunately it goes from bad to worse during said rise and fall.
I noticed you had the pre amp on too maybe not a help on the low bands .
de Ian vk5cz …
i am sure it will be back as soon as the offending item is switched back on.
is there something good on TV?