The other day I had a large chunk of 20M (14.265-14.295ish) wiped out by a carrier at 59-59+20. Worst beaming east from here in the SE UK. I thought it a local problem but in a perverse pleased I was glad that DL and OE etc, were experiencing the same problem judging from spots. Next time it happens I will record it and post here - do people think it a good idea to swap notes about such things that disrupt being able to hear SOTA activations etc ?
Slightly confused as to why a carrier would be 30kHz wide. Was it modulated, or moving?
If it was the sound that I think it was - rather more than a simple carrier - it is over the horizon radar, successor to the late unlamented Woodpecker.
It is always useful to receive a report of QRM on one of the recognised SOTA frequencies, mainly for the reason you mention - for chasers it demonstrates whether it is a local problem or causing interference over a wide area; for activators it can help them to move slightly in case they are not hearing the problem at their location.
Hello Brian, spot on - I got a screen shot of it.
It suddenly comes on. Sometimes for hours 8(
Not a carrier then. Some sort of wideband transmission.
Also on 14.2625 through 14.275 at the moment here.
Hello Richard, yes it is a big carrier - not simply wideband.
I sampled it on the SA. Also on the Flex checked it on DSB,FM,LSB,USB etc. etc. etc. etc.
A military source I guess. Oh well.
Reporting it to the relevant organisation would be useful:
“It is always useful to receive a report of QRM on one of the recognised SOTA frequencies”
Yes I thought so. I know from the past you have posted information about the CW part of the band being plagued.
Until I saw the spots indicating the same problem I was going to go on a walk with the 897 on battery !
Done that x8! Over last two years - not much back.
I think maybe that’s GM/SI-110 and those are offshore sea stacks (Including OMoH)
I don’t think you get woodpeckers on sea stacks - gannets, perhaps!
The give-away is that it is frequency agile and seems to move as the muf changes. Perhaps it would be a bit naughty to record it and send it back to get confused with reflections!
Someone should ask that awfully nice Mr. Putin if he would: “Пожалуйста, наведите курсор радар OTH из любительских диапазонах? Спасибо.”
It would be a pretty naf system if it was that easy to spoof it. I suspect it’s a bit cleverer than that!
It’s also no Woodpecker thankgoodness. Modern signal processing means that it’s relatively low power and narrowband. The Woodpecker on the other hand was very high power and very wideband. I recall that you could often hear it as breakthrough on 10.7MHz IF radio systems
"Modern signal processing means that it’s relatively low power and narrowband. "
Sorry but this comment is nonsense.
This is a high power transmission, shifted downwards in frequency later in the day and is a stable signal of carrier. Anyway time to go for a walk in the forest before it rains.
Not to those who are practicioners of signal processing Mike.
It’s only 30-40kHz wide. Woodpecker was up to 800kHz wide. Entirely different scales. It’s anything but wide, it’s not much wider than a typical eejit’s ESSB signal! Whilst it might be loud in our receivers, it doesn’t mean it’s high power in the Woodpecker sense. i.e. MW ERP
It may be no woodpecker but it is just as frustrating when it is sitting on a SOTA activation! I reckon I’ve probably lost four chases this week because of it. I don’t remember ever hearing the woodpecker as IF breakthrough but it was certainly shatteringly strong at times and could wipe out the whole of an amateur band in one go. If the Russians set up a chain of “Son of Woodpecker” and they avoid overlapping frequencies then I can see those days returning.
[quote=“G3CWI, post:15, topic:9247”
…“It would be a pretty naf system if it was that easy to spoof it”.
We used to spoof the Woodpecker and hurl it back at them all the time, myself and a guy in Los Angeles. It seemed to work for awhile. This was back when modern tranceivers like the 940 had a second noise blanker just for old Woody.
If it was that easy how come the USAF didn’t cotton on?
Lots of radio amateurs thought they could get the woodpecker to move.