Hearing myself respond to my Call

So, if you ever wish to purchase a lot on the ionosphere remember one thing: propogation, propogation, propogation.

Fun stuff, huh.

73, Bob

 

Back in the late 80's, I heard the last few words of my CQ on 10m SSB.  At first, I thought I was being screwed with, but when I thought about it, I realized that it was impossible to have recorded my words and played them back at the same time with a short delay (less than a second or two).

I never realized there were studies/arcticles done on this -- I'll have to check those out.  

73,
Joe

 

What signal report did you give yourself? You did QSL, didn't you?

 

That idiot has been doing that on 20 meters for about a year. At least the quality is good enough to check your audio.
73, Dave WA2DXQ

 

I had this happen a couple years ago on 11 meters where I just heard the last little bit of my CQ.I too thought it was probably someone sending back a recording.Having heard of this before I thought I would try again but on another freq. I quickly jumped up 15kc +/-and tried again and heard the last part of my CQ 3 times in as many calls then no more. If it was some joker playing around, I dought he would have found me quick enough for my first call on another freq and dought he would just stop. The time lapse was not right UNLESS I was picking it up the SECOND time around. I understand the losses, especialy on the "second trip" but under the circumstances given I still believe this is what happened. Hey...Ol' Mother Nature has done some stranger things right?

 

Dave WA2DXQ has a point but there are probably only one or two pranksters out there doing this BUT
how does this explain the numerous historical instances of this phenomena with delay durations of MINUTES
long before modern recorders and SSB were even thought of

Like many mysteries there is more to this than meets the eye

 

This all depends on exactly what you heard.  For instance, if you gave a ten second or so call, then heard the entire thing you said come back, I'd say you were the victim of a prankster.  If you were hearing only the tail end of what you said, I'd say you were  hearing a reflected signal of your own transmitter.  I had this happen in my CB days during heavy sunspot cycles.  While I usually heard phasing and echos (and I'm not talking about the echo toys) from others, I did hear my own transmitter keying down a few times.

 

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC0LNU @ Oct. 23 2002,10:23)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KB8DPN @ Oct. 22 2002,10:51)</td></tr><tr><td id="QUOTE">So I gotta know -- Did you talk to yourself?

[/QUOTE]<span id='postcolor'>
If you answer yourself on an amateur radio does that all your wires aren't quite connected?[/QUOTE]<span id='postcolor'>
I gotta know, do you send yourself a QSL card and do you request an SASE?

 

Well, upon first blush I figured it had to be a phenomenon of the way society has gone in years past. I have heard such things before on 20 and other bands and always attributed it to the playful, albeit illegal, activity of folks without a life. It seems even good buddies can get a ham ticket. Perhaps if the last milliportion (is that a word?) was heard by the transmitting station I would tend to believe it was the real deal. Anything else IMHO is a hoax. G3SEA has an excellent point also. Now if I could only get my signal to propagate that well..........  

 

While it is true some pranksters, and some idiots, will record a signal and play it back as a means of deliberate interference, the phenomena of LDE has long been known, but never explained. QST did a brief article on it in the early 1960s. During that period of time, Stanford University's Physics lab also was studying the phenomena. It is possible they may still have some information left over from that study that someone could find on their web site, or by contacting them otherwise.

I have heard LDE (Long Delayed Echos) perhaps 8-10 times in the 47 years I have been involved in communications and ham radio. I heard them only once, though, in the ham bands, on 20 meters. Most of the LDEs I heard were on HF government communications. They were not recordings played back.

In one situation, as an example, we had a "guard tape" sending a VVV DE (call) tape for duration of one minute, then monitoring for one minute. The code was automatic, by punched tape. During the tape, the VVV DE CALL was repeated for a total of three times, followed by the QSX info. The LDE heard was the call sign repeated twice followed by the QSX and then it disappeared. It neither faded in nor faded out, but was as though it was just "on" and then "gone." Instantaneous.

We also had echos of voice transmissions now and then, but most of the instances I heard personally were on CW.

There were numerous theories, but the delay in the example I quoted was about 18-20 seconds, far too long for normal round-robin to solar system objects, and too short for round-robin to the sun. Most delays reported by hams are on the order of 5-15 seconds.

There are, though, reports of AM broadcast stations being echoed, even after signoff, and I think there was a report of an AM station being heard not several seconds but several minutes after signoff.

Someone in an earlier post mentioned sunspot cycles and in looking back I see that may could be a link.

Someone suggested a radio wave ducting around the planet several times and then suddenly breaking back through and being heard again, after perhaps a dozen turns around the stratosphere. As far as I know, no-one has ever explained adequately this phenomena. Of course, there are the fringe folks who tell us it is a parked space ship from Planet Greenman, trying to let us know it is here by returning our radio signals.

It is actually a natural physics act we have not explained, and probably haven't because we have not devoted much effort to doing so.

LDEs have been around since the beginnings of radio, but were only seriously studied briefly in the 1960s. I doubt anyone is studying them now.

73
Ed

 

The phenominon is called LDE or Long Delayed Echo. Your signal bounces around the earth between the surface (land or water) and one of the E/F/? layers. I've experienced it also. Good DX! You get to send yourself a QSL!

 

Yep, happened a few times when I was in Egypt back in 1984 as KA4SBE/SU. The ARRL didn't accept the card I made out to myself for DXCC credit though. Took darn near a year to get through the bureau too! Had to have a postmark from the right country you know.

 

I had the LDE experience, too - on CW. I heard my fist sending my call - right after my first call (callsign sent once at about 25 wpm) to a station in Mauritius.

No doubt in my mind this was LDE!

73, Bob

 

An interesting article on the phenomena of LDE can be found on Bill Continelli's (W2XOY) "Wayback Machine" radio history series.  Direct URL to the chapter is:

http://www.qsl.net/ecara/wayback/page31.html

 

I have experienced it in a different way.  A megawatt pulsed 10 rep rate and extremely fast recovery time of the receiver for backscatter (Woody wood pecker).  The backscatter was recorded on black and white film as witnessed proof.  You may have heard me jumping wavelengths, but mostly around the low end of the 20 meter ham band.

Sorry fellows, but that was my job.

    A megawatt plus a Rhombic with 20 db gain sure showed me plenty of echoes.

                         W6th