[ARC5] LDE

[Kenneth G. Gordon]

On 18 Jul 2013 at 7:37, Bruce Long wrote:

> yes I think I heard one as well and there is scientific documentation-
> not much but some- of the phenomona.

The first one I experienced was VERY clearly an LDE. I was operating as 
NCS on PAN (a CW traffic net) back in the 1960s or 1970s sometime. I was 
operating full break-in with a KW rig I had then, a TechRad T-350-XM (wish I 
still had that rig).

I began hearing a weaker signal between my sending and I thought it was 
someone trying to break me and join the net.

The signal got stronger and stronger, and I finally figured out it was my own 
sending coming back to me with a significant delay

The echo built up to a good 579. I tested it by sending "long dots", and 
listening for the reply, which was, at its shortest, about 1/2 second or so, as I 
remember it.

It built up to a peak in loudness, then slowly faded out and finally 
disappeared.

The time between my sending and the echo became longer and longer as it 
faded out.

The length of time this LDE lasted was on the order of several minutes from 
when I first heard it to its final fade out.

The second such incident which occurred to me was much less "impressive", 
only lasting a few seconds, and took place at least 25 years after the first 
one. I don't remember much about that one, except that it did occur.

What little documentation I have read on these things never really satisfied 
me as to the explanation of the cause. "Ducting" was one.

It is still a complete mystery to me.

Ken W7EKB