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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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6th Aug 2015, 10:26 pm | #1 |
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There's 'DX' - and then there's real 'DX'!
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6th Aug 2015, 10:34 pm | #2 |
Octode
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Re: There's 'DX' - and then there's real 'DX'!
25 odd years ago when Helen Sharman was up there I tried to contact her on two metres. She said that all she could hear was a wall of noise as hundreds of amateurs were trying to call her. Just the odd one peaked out of the noise so that she could respond to that individual. Bit like most pile ups. At the time I was sad that it wasn't me she heard.
I made a cassette recording at the time which I should still have I guess. Jim |
6th Aug 2015, 10:56 pm | #3 |
Dekatron
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Re: There's 'DX' - and then there's real 'DX'!
It's interesting, but 220 miles or so line of sight isn't really DX. Anyone with satellite TV is routinely receiving signals from about 100x that distance. Moonbounce is somewhat further again....
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6th Aug 2015, 11:04 pm | #4 |
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Re: There's 'DX' - and then there's real 'DX'!
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6th Aug 2015, 11:26 pm | #5 |
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Re: There's 'DX' - and then there's real 'DX'!
It might not be DX but it's a rare positive article about amateur radio in the mainstream press. If it piques the interest and attracts new blood into amateur radio then it's worth publishing, yes?
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7th Aug 2015, 10:31 am | #6 |
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Re: There's 'DX' - and then there's real 'DX'!
I am puzzled why something which was being routinely done some years ago is suddenly in the news again. Does RSGB have a new Press Officer?
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7th Aug 2015, 11:24 am | #7 |
Nonode
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Re: There's 'DX' - and then there's real 'DX'!
I agree it is not Moonbounce - but it is the newspaper/TV media 'silly season' at the moment...
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7th Aug 2015, 11:52 am | #8 |
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Re: There's 'DX' - and then there's real 'DX'!
Main thing it helps promote our hobby.
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7th Aug 2015, 7:36 pm | #9 |
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Re: There's 'DX' - and then there's real 'DX'!
What callsign does a space station located operator use? /M, /SM (likeMM)?, and should it change depending on whether it's over land or sea?
Maybe anything you like if space is not subject to any jurisdiction.
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7th Aug 2015, 8:09 pm | #10 |
Octode
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Re: There's 'DX' - and then there's real 'DX'!
In 1992 Helen Sharman was using GB1MIR when I tried to call her which I think was allocated for the purpose. I can't remember whether she holds an amateur licence herself nor can I remember what frequency she was using but think it would have been 145.550
Jim |
7th Aug 2015, 9:05 pm | #11 |
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Re: There's 'DX' - and then there's real 'DX'!
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7th Aug 2015, 10:25 pm | #12 |
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Re: There's 'DX' - and then there's real 'DX'!
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7th Aug 2015, 11:50 pm | #13 |
Dekatron
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Re: There's 'DX' - and then there's real 'DX'!
I heard the space station loud and clear some years ago, they were talking to someone, unfortunately it wasn't me.
Peter |
8th Aug 2015, 9:48 am | #14 |
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Re: There's 'DX' - and then there's real 'DX'!
Pluto bounce is real dx
D |
8th Aug 2015, 11:50 am | #15 |
Nonode
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Re: There's 'DX' - and then there's real 'DX'!
Dave,
I suspect you would need Jodrell Bank or Areceibo for Plutobounce ! Either way, a "bit" more aerial than a 4 element Channel B2 on 50 Mc/s; which was real DX for TVs in the BBC North Hessary Tor 405 Line transmitter fringe... |
8th Aug 2015, 12:29 pm | #16 |
Octode
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Re: There's 'DX' - and then there's real 'DX'!
I suspect Dave that Pluto bounce would be below the noise level CW with computer assistance.
I've heard about very slow morse so far below the noise level that human ears cannot decipher it but don't know much about it. I'm not keen on anything that takes away human skill despite my own skill level being a bit lacking these days. Jim |
8th Aug 2015, 1:25 pm | #17 |
Dekatron
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Re: There's 'DX' - and then there's real 'DX'!
Most E-M-E stuff these days [and for the last decade or so] has used synchronous digital modes with accurate clocks both ends, where the receiver 'knows' when to expect a signal-element's edges and transitions; coupled with error-correction this can indeed recover signals reliably from negative signal-to-noise situations where a human ear can't even tell there is a signal present.
Similar techniques are standard on the 136 and 472KHz ham bands [though there the major issue is the narrowness of the allocations and inefficient antennas]. If you want a *real* space-radio challenge I think Sunbounce would be the thing to try! |
8th Aug 2015, 2:31 pm | #18 |
Octode
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Re: There's 'DX' - and then there's real 'DX'!
I suppose if you're the designer of this stuff or a professional user it would be very useful but it's getting to the edges of extreme nerdity.
I have a friend who had a demonstration of some sort of system using these techniques but he found that compared to doing it all manually it was quite yawn inducing and didn't stay to the end. No human achievement involved. Each to his own I guess. Jim |
8th Aug 2015, 3:58 pm | #19 |
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Re: There's 'DX' - and then there's real 'DX'!
There *is* a lot of human achievement involved, but it's in the design phase. It's very satisfying developing something special. The first signals you hear on the first radio you've built you remember forever... and the first things you hear on a radio you've designed from scratch is a big step further.
Using a lot of things is boring once they've been brought to a state approaching perfection. DXing has become boring. All the places being sought now are difficult not because of difficulties in doing the radio stuff, but are rare because no-one active lives there. For example Mount Athos is sought after DX, but Greece isn't. Earlier this year I was at a thoroughly excellent talk about a Expedition to Nevassa Island. The US wildlife people forbid any landing and a group of DXpeditioners had to campaign long and hard to get permission. Part of the deal was that they had to pay for government employees to accompany them to police them. It was an impressive amount of work and an incredible outlay. I thoroughly enjoyed the talk and I learned new things about the world, but I have to admit what they did was no real achievement in radio terms. Nevassa is sought after, but there are other populated and active islands around it. Whenever they do do a manned expedition to Mars, it's likely that the people going will have radio gear set up for something to break the monotony of a very long journey. Also the space agencies see it as publicity that might aid their politicking for funding. David
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8th Aug 2015, 5:14 pm | #20 | |
Dekatron
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Re: There's 'DX' - and then there's real 'DX'!
Quote:
These days you solder a bunch of SMD components to a PCB, then spend a few weeks learning the art of DSP programming before going on-air with the likes of WSPR and getting contacts with well-below-the-noise stations, using less transmit-power than an average flashlight. Diff'rent strokes for diff'rent folks I guess. I still prefer SSB though these days for me its creation and decoding is usually done digitally, and rather than going for DXCC etc I prefer the challenge of working the same station every day for 100 days. |
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