[Elecraft] Propagation Modes

Sun Aug 10 11:47:01 2003

Vic K2VCO wrote:

>Some years ago when I lived in 4X, I recall getting up at about 
>sunrise and hearing the 20-meter band apparently dead.  I tried the 
>following  experiment:  using high power and full QSK CW, I called 
>CQ while rotating by antenna.  In certain directions, I heard very 
>strong echoes  between the dits and dahs.  The timing was such that 
>I was convinced that I was hearing my signal the long way around.  I 
>assumed that this was 'normal' multihop propagation, and I was 
>surprised that I never got any answers from DX stations!  Now I 
>think it was a chordal mode which was not coming down to earth 
>except locally and (perhaps) in places where there wasn't anyone 
>listening.

Both myself and Steve GW4ALG experienced this phenomenon last year in 
the ARRL 10m contest while running our K2s at 5W. At first I didn't 
believe my own ears - ie I was hearing my own morse coming back in 
the QSK gaps - until Steve confirmed he had heard the same. Chordal 
hop is one theory, but certainly the signals seemed to have come 
right back round the world - working yourself on long path! You 
certainly don't need high power, but not heard it lately in the 
present lousy conditions.

73 Dave G3YMC

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