|
General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
|
Thread Tools |
22nd Sep 2020, 5:02 pm | #1 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 631
|
Echo on short-wave station
Last Sunday, I heard a station in the 19m band on 15770kHz using my Trio R-5000 receiver.
It had a weird echo effect and I'd be interested to know what you think could be the cause of this. I've posted a video onto YouTube here :- https://youtu.be/ex23MV_vPNQ so you can have a listen. Andy
__________________
G-QRP #12697 |
22nd Sep 2020, 5:11 pm | #2 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
|
Re: Echo on short-wave station
Do not think it will be an Aurora at that frequency.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S |
22nd Sep 2020, 5:38 pm | #3 |
Heptode
Join Date: Apr 2009
Location: Scratby, Norfolk, UK.
Posts: 651
|
Re: Echo on short-wave station
Hi,
I remember hearing that type of 'echo' many years ago. It could be a combination of both long and short path reception. Kind regards Dave |
22nd Sep 2020, 5:47 pm | #4 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,324
|
Re: Echo on short-wave station
Weird isn't it? I think that's far too long for long and short path reception which has a delay of about 0.14 seconds. What you're hearing is from two different transmitter sites intending to beam to different zones. Each site's audio is fed via a different route; one may be satellite, the other an internet link, or two different internet links and the audio has all sorts of digital delays.
Propagation at the time and your location means you can hear both signals. This phenomenon gets reported from time to time. I helped them unpick it on the 'Soldersmoke' podcast a few years ago. Ian PS: There is also the very odd phenomenon of long delayed echoes with delays of many seconds. Unfortunately it's vanishingly rare with no plausible mechanism - so tends to be put in the "can't be explained, too rare so doesn't exist" box! I think there are some theories now and it's being accepted as a real phenomenon. Last edited by Ian - G4JQT; 22nd Sep 2020 at 5:53 pm. |
22nd Sep 2020, 6:57 pm | #5 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,324
|
Re: Echo on short-wave station
Listening again, the two voices seem to fade up and down at the same time suggesting they come from the same transmitter. It appears to be WRMI Okeechobee - just one transmitter site. Maybe they had two feeds (main and standby) plugged in at the same time by accident...?
|
23rd Sep 2020, 2:56 pm | #6 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 631
|
Re: Echo on short-wave station
Thanks everyone for your thoughts about this.
Many possibilities but I guess we'll never know for certain ! Andy
__________________
G-QRP #12697 |
23rd Sep 2020, 4:44 pm | #7 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,899
|
Re: Echo on short-wave station
There are numerous possibilities.
Long path versus short path Two transmitter sites covering different geographies without mention of each in the other's area. Space aliens David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
24th Sep 2020, 1:03 pm | #8 |
Rest in Peace
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
|
Re: Echo on short-wave station
|
24th Sep 2020, 2:18 pm | #9 | |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,324
|
Re: Echo on short-wave station
Quote:
The phenomenon has a long history going back to the 1920s - with one scientist linking them with an alien Bracewell probe. A German radio amateur managed to record an example (or claimed to) from his own transmissions in the past decade or so, but got so much flack from the we-can't-explain-this-so-it-must-be-fake brigade he removed it. Not an attitude conducive to researching erratic and not understood stuff. But an attitude that many people embrace... Wikipedia has some sensible stuff about LDEs. https://en.wikipedia.org/wiki/Long_d...ive_hypotheses |
|
24th Sep 2020, 9:55 pm | #10 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 631
|
Re: Echo on short-wave station
I thought the same as Al
however, I take your point about losses Ian. The conditions higher up in frequency were unusual that weekend - a radio amateur pal of mine had a contact with a German station on 2m SSB using 100W. Andy
__________________
G-QRP #12697 |
27th Sep 2020, 11:29 pm | #11 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,113
|
Re: Echo on short-wave station
I'd just read this thread before going to bed the other night, and then I turned on a portable I keep in the bedroom to check if there was any lightning going on locally. Switching to MW it landed on a random channel with the most wonderful collection of echos and pre-echos of Spanish speech. Tonight I found the channel on something with digital readout and it turns out to be RNE 5 on 1125 with, appropriately 5 tx all 10kW
Not quite as echoey but still noticeable
__________________
- Julian It's good here |
28th Sep 2020, 9:33 am | #12 | |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
Posts: 1,324
|
Re: Echo on short-wave station
Quote:
The modern thinking is that in the daytime service area, you only hear the signal from your intended transmitter. Unfortunately, night sky-wave interference allows you to hear other stations on that frequency. Spain is a good case to demonstrate this because they use many local MW transmitters for their national networks and they don't bother with synchronising the audio. I'm sure retired BBC transmitter engineers will remember how not only were all MW network transmitters' carriers kept to 0.05 Hz, but the audio was in phase (as far as possible) that fed each transmitter. That was easier when the modulation came down analogue 'music lines'. These days it's a dog's dinner of digital feeds - and no one cares how it sounds. I think Five Live isn't quite as bad, but I don't think the network frequency sync is kept to 0.05 Hz, neither is as much attention kept on the phase of each transmitter's modulation as was the case in the 1980s... Ian |
|
28th Sep 2020, 9:42 am | #13 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
|
Re: Echo on short-wave station
Group sync +/-0.05Hz ... nicely remembered, Ian
Guy "Oh, hearing Okeechobee ... Oh, hearing Okeechobee ... Oh, hearing Okeechobee - That's what it's all about" (sorry, couldn't resist it)
__________________
"What a depressingly stupid machine." [Marvin: HHGTTG] |
28th Sep 2020, 12:03 pm | #14 | |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,687
|
Re: Echo on short-wave station
Quote:
I'd be keeping that left leg in if I were you...
__________________
Regds, Russell W. B. G4YLI. |
|
28th Sep 2020, 1:18 pm | #15 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,899
|
Re: Echo on short-wave station
Have you heard Bill Bailey's Kraftwerk version?
Brilliant! https://www.youtube.com/watch?v=dwaxWoJPUC0 David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
28th Sep 2020, 1:27 pm | #16 |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,687
|
Re: Echo on short-wave station
I have now! Brilliant indeed.
Did he ever come home, Bill Bailey? Did he ever come home? Is she still moaning the whole day long?
__________________
Regds, Russell W. B. G4YLI. |