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Re: primary close to ground?



Original poster: Paul Nicholson <paul-at-abelian.demon.co.uk> 

Malcolm wrote:

 > Having the primary close to the ground lowers its unloaded Q
 > (i.e.  with the gap shorted out) substantially.

Perhaps we should be persuading Terry to hook up the pinger and
scope, with a view to doing some more Q variation experiments.

Previous experiments have looked at the Q of an isolated secondary.

  http://www.abelian.demon.co.uk/tssp/qvar070402/

It would be interesting to do something similar with a typical
primary resonator, at various heights above the ground.

Another issue which could also be tackled is that of secondary
grounding.  The relative merits of 'deep' grounding (ie long
stakes); 'remote' grounding (running the secondary base out to a
ground point some distance from the coil); 'shallow' grounding
(lots of shallow stakes), and counterpoise (artificial ground
plane), could be revealed in terms of their effect on the Q
factor and resonant frequency.

--
Paul Nicholson
--