Peter,

Cave radio people have for some time been wondering about the origin of the 
Galloping Horses effect.  I believe the term was coined by Jean-Jacques 
Fauchez, F6IDE, but he is now a Silent Key we cannot ask him.

May we reprint your explanation as a Letter to the Editor in our next issue, 
please?  I would of course send you a copy of the text beforehand for you to 
agree the contents.

73,
John Rabson F/G3PAI
Commissioning Editor
Cave Radio & Electronics Group Journal

*********** REPLY SEPARATOR  ***********

On 08/03/2006 at 09:45 Peter Martinez wrote:

>>From G3PLX:
>
>It wasn't Rugby that went off yesterday but Lessay. As luck would have it
>I
>was trying to debug some LORAN receive software that morning, and I
>couldn't
>figure out why it wouldn't work. It seemed to work in the afternoon and I
>couldn't figure that out either until the screenshot from Markus revealed
>all!  The moral must be - don't try to debug LF receive software on the
>first Tuesday of the month!
>
>Rugby transmits a regular group of 8 pulses at 14.85/sec., and on it's own
>that would give a very regular buzz, although at a rather lower rate than
>a
>fluorescent light. When Lessay is on, it transmits both at 14.85/sec and
>13.11/sec and the 1.5Hz beat between these gives the galloping effect.
>
>With Lessay off, the galloping stops. At least this is true in the UK.
>
>73
>Peter