Talk:Long delayed echo

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[edit] Possible explaination

I have encountered LDE's on some DX stations (VE2 and western EU) from Australia over the past 6 years or so... ie not my own echo's, but delays between the DX main signal and then replications of their signals..

Being an engineer (PE) with a very practical bent... I simply put this down to the effects of signal progression in a waveguide - where it is possible to have a signal moving through a waveguide down to 1% to 2% of the speed of light or less... A classical microwave worked example is referred below.

I am confident the ionosphere can 'fabricate' a sizable waveguide style duct over short periods. While this would and could easily explain a single signal delay, some discontinuity in the 'ionospheric waveguide' could generate return loss blips... hence echo's.

Anyway, I figured I'd share my idea with you... as I sort of took this for granted for the past 25 years that every engineering student who studied microwaves could see this phase velocity effect in practice on the HF bands. (UNSIGNED by 203.185.214.196)