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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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5th Apr 2017, 3:25 pm | #1 |
Hexode
Join Date: Nov 2010
Location: Market Drayton, Shropshire, UK.
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Strange signal on 62mc/s
Over the last few days I have been looking for possible DXTV on 62Mc/s (E4)
In The moring there is a signal sounding about 800-900C/s on this Ch the video is a lot of line, like a modulated signal from a generator is beening feed in.The signal is coming from the SE and the tv is set to 6M/c sound , Does any one know what this is. Regards Derrick Last edited by 1955APREN; 5th Apr 2017 at 3:26 pm. Reason: spelling |
6th Apr 2017, 9:03 am | #2 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
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Re: Strange signal on 62mc/s
As you are seeing it every morning my guess its a noise carrier or interference from some gadget that someone has bought, or has just installed. Sadly this is an all to common problem these days. If the signal is of constant strength then the source of the signal is close by.
The analogue E4 channel has not been used across Europe for some years. The nearest E4 analogue TV transmitter is in the Middle East and is only occasionally received in the UK via double hop Sporadic E or via the F2 layer during spells of high solar activity.
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6th Apr 2017, 10:45 am | #3 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
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Re: Strange signal on 62mc/s
A wide buzzing which has been heard in both broadcast and amateur bands, so strongit has broken into receiver IF's, is a Russian OTHR (over the horizon radar) which does
not seem to comply with any regulations. |
6th Apr 2017, 3:19 pm | #4 |
Nonode
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,495
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Re: Strange signal on 62mc/s
I agree with Simon. However I have received analogue TV on TV channels R1 and briefly R2 about 8/9 months ago - strong enough to see the picture (Russian programming), so it is no mis-identification. Hence there is the outside possibility that it is DX-TV...
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6th Apr 2017, 8:34 pm | #5 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,350
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Re: Strange signal on 62mc/s
Ref the third message, is that Russian noise a 60 year old reflection of the WOODPECKER. Younger listeners won't know of it, but it blanked out many bands, as Uncle Joe and his successors did not want the workers to hear VOA or other western broadcasters. The astrophysics people claim to "see" what happens billions of years ago, so why not this recent stuff.
Les. |
6th Apr 2017, 11:31 pm | #6 |
Octode
Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 1,223
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Re: Strange signal on 62mc/s
The Woodpecker (or "Ratatatski") was not associated with broadcast jamming. It was an early warning system for detecting ICBM's and it would pop up all over the HF bands. The remains of the antenna arrays have been extensively documented by enthusiasts with pictures and videos posted on the internet.
The UK / USA had one too, at Orfordness, but the contractors never got it working properly so the project was quietly abandoned after huge expense and the site was dismantled. There are now numerous OTH radars that hop around the HF bands, including the higher amateur bands where they cause great annoyance. Most of them look like a rapid sweep 20kHz wide and can be clearly seen on a wideband SDR. But I don't think any of them go up as high as 60Mhz. |
7th Apr 2017, 7:51 am | #7 |
Moderator
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Re: Strange signal on 62mc/s
If you're interested in OTH radars you can lookup the following names:
The one at Orford Ness was called Cobra Mist and seemingly never worked. You couldn't burn money as fast. It was intended to be built in Turkey, but Turkey decided it didn't want the attention. Cobra Mist got recycled as a world service transmitter site and the original fan of antennae got changed. You can see the pattern in the ground on satellite pictures, though. The Russian one was called Duga-3. it was and still is BIG. It changed the world in more than one way. The power supply built for it and the town which serviced it was called Chernobyl... so you know where to look on Google Earth. The American equivalent was called Conus-B I suppose OTH signals are a guide to where the MUF is. David
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7th Apr 2017, 8:53 am | #8 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
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Re: Strange signal on 62mc/s
8-9 months ago would take you back to the middle of the last Sporadic E season which generally runs from May to August. I received the Ukraine and Russia several times on R1 and R2 last year. Make the most of it as DSO is coming to both countries very soon.
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7th Apr 2017, 9:13 am | #9 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
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Re: Strange signal on 62mc/s
Woodpecker is long gone, the new Russian is called "Container". However I now believe
the signal may be a chinese OTHR. Note that many HF transmitters have VHF harmonics, easily propagated by SpE. I have received plastic welding equipment DX radiating on 27MHz, but they do not issue QSL cards, sadly. |
7th Apr 2017, 10:44 am | #10 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,397
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Re: Strange signal on 62mc/s
With an HF receiver that reached to 32MHz or so, the 2nd harmonic of some 19m broadcasters could frequently be found with a low-strength but clear signal.
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7th Apr 2017, 11:21 am | #11 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
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Re: Strange signal on 62mc/s
Australia has a massive system called JORN
https://en.wikipedia.org/wiki/Jindal..._Radar_Network that has a 1000km to 3000 km range, but I guess it's a bit too far away to be the cause! One of my (now deceased) colleagues was involved with it when I was with GEC. It was highly classified at the time, but now you can read all about it on the web. |
7th Apr 2017, 11:22 am | #12 |
Nonode
Join Date: Jun 2009
Location: Herefordshire, UK.
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Re: Strange signal on 62mc/s
Hybrid tellies,
I agree with most of what you say except that I have heard absolutely no meteor pings on R1 - and they were characteristic of the SpE DX-TV days. So I wonder whether what I saw was a result of some form of double hop... ? |
7th Apr 2017, 5:58 pm | #13 | |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,005
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Re: Strange signal on 62mc/s
Quote:
If it started unsquelching I knew things were looking up. I also used to scan for 'stuff' in the 30-40MHz area - which was used both by the US police and various taxi/Volkspolizei/security-services in the then-Warsaw-Pact countries. Their transmissions were a good early-warning of enhanced propagation. |
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8th Apr 2017, 9:07 pm | #14 |
Hexode
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
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Re: Strange signal on 62mc/s
I have heard something that sounds like the woodpecker on 14Mc/s or thereabouts the pulses sounds softer and definatley not as loud as the original pecker (can I say pecker on here?) so not sure exactly what it is. Yes I too have heard a loud buzzing that covers maybe 100 Kc/s or so of wherever it is but I haven't heard it so much recently but then again conditions have been a bit grim lately
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9th Apr 2017, 9:17 pm | #15 |
Hexode
Join Date: Nov 2010
Location: Market Drayton, Shropshire, UK.
Posts: 485
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Re: Strange signal on 62mc/s
Thanks everyone for all your replies very interesting thoughts about this, but I have got a big confession to make about this thread. On Fri morning I was able to take a photo (enclosed) of the signal. Today the signal was present PM, rotating my aerial showed it was coming from the SE. Now my shed is quite a way up the garden, about 12 metres from my bungalow, but it is on the NW side of the bungalow. It was now time to switch off all things in home. I do not think you will need three guesses to know what happened when my computer was switched off, Ch4 signal had completed gone. Oh boy have I got a red face. I thought that modern equipment did not radiate.
Regards Derrick |
9th Apr 2017, 10:07 pm | #16 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
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Re: Strange signal on 62mc/s
You shouldn't be getting that much RFI - modern digital gear is noisy but not that noisy. I suspect you have a fault, maybe a bad PSU. They can soldier on for years, apparently working normally while churning out horrendous levels of RFI.
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9th Apr 2017, 10:11 pm | #17 |
Moderator
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Re: Strange signal on 62mc/s
Modern equipment radiates like ********
Computer manufacturers have to go through the 'B' level emc tests, but instead of running dear old windows, they are allowed to run a randomising programme, which spreads al their muck over a wider bandwidth than that specified for the EMC measuring receiver, so most of it never gets measured together. Voila! a pass! Then when you start tu run the CPU and graphics normally you get heaving great sproggies all over the place. Then, pass in hand, some nice eastern gents start removing the emc filter components. Just lok in a cheap PC PSU and spot the holes for missing capacitors and the wire links where inductors ought to be. The EMC test scrambling isn't general knowledge, but the vanishing filter components are. David
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9th Apr 2017, 10:23 pm | #18 |
Hexode
Join Date: Nov 2010
Location: Market Drayton, Shropshire, UK.
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Re: Strange signal on 62mc/s
THank Paul I think you may be right Computer is a Mac os 10.9 that I had for about 3yrs and have only just seen signal over last week . I will leave it till it goes bang
Derrick |
9th Apr 2017, 10:51 pm | #19 |
Moderator
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Re: Strange signal on 62mc/s
As I said, it may go on for years like that.
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10th Apr 2017, 8:59 am | #20 | |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
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Re: Strange signal on 62mc/s
Quote:
I would not be to embarrassed about the source of the noise, well done for tracing it, it has happened to myself and probably others as well. A few years ago I found the the 31m and 25m bands suddenly disappeared under a load of noise. For ages I was blaming everyone in my locality until I did some detective work with a portable HF receiver and traced the source to an overheating lead acid back up battery in our burglar alarm.
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