Hi Ian and Group.
On Mon, 14 Apr 2003, Ian Kyle wrote:
Some of you will have noticed that I have been venting my frustrations about
the title subject on the reflector recently and that I mentioned an
interesting anomaly in the earthing arrangement, so over the weekend out
came the deerstalker, cape and meerschaum and the investigation commenced.
The anomaly is this; after finishing reworking a number of things as
detailed in an earlier posting, the there was a sensible increase in antenna
current of about 30 - 40%, so I set about tidying things up round the
'dogbox'. Then to my astonishment the next test produced a further increase,
the resultant increase totalling about 75% and the BK could be driven right
into saturation. Obviously something had changed, but I had not consciously
altered any of the settings.
I do not know realy why is this. But may be (???) it is somthing similar
to my theoretical result reported here about year ago. If cable is
elevated from the ground significaly more then cable diameter it can
employ as elevated conterpoise.
About year ago I derive formulas wich show elevated conterpoise is much
better then conection to the ground or burred conterpoise. Conection to
the ground in shack may be isolated on RF by some inductance. Or ground
in shack is screened by some metal construction (in this case conection to
the ground seems not increase losses). Certanly this should be tested in
some experimentaly way.
Any way ANY additional connection to the ground NOT
evidently decreases loss. Seems loss can increase in some cases.
73 de RA9MB/Alex
http://www.qsl.net/ra9mb
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