From: "jannsen" <0482183881-0001@t-online.de>
To: rsgb_lf_group@blacksheep.org
References: <000901c08247$aeaaec60$5103883e@default>
Subject: LF: Re: Loading Coils/g2ajv/Roger
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Date: Fri, 19 Jan 2001 23:20:49 +0100
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MAL HAMILTON schrieb:

>
>.........................
> The loading coil is not just a matching device, it is also a primary source
> of vector potential and it is the vector potential, rather than its
> offspring, the magnetic and electric fields, which is the fundamental
> source of electromagnetic radiation.  It is therefore advantageous to place
> the coil upright at the base of the antenna.  Furthermore, as a large
> component of the vector potential is locally concentrated in this region,
> it may be possible to gain a few dBs by placing an aluminium or copper
> plate, somewhat larger than the diameter of the solenoid, a few centimetres
> under the solenoid, insulated from the earth but it may be connected
> directly to the TX ground terminal.  (It reflects the vector potental
> instead of allowing it to be absorbed in the terrain, but DON'T stand on
> the plate to adjust the solenoid whilst running at full power !!!).
> .................................
> 73,  Roger, G2AJV.
>
Hello Roger es all,
thats it! Some 20 years ago I got the out of fashion equipment of an 
lf-transmitt-test-T-antenna from Pinneberg (DCF49). the plate u mentioned
has been saved in my vy big junk-box until I myself built a T-antenna some month 
ago. isolated 40-m-radials (orignaly 80 radials in Pinneberg) increased its 
effect. the loading-coil 40cm in diameter was centre-positioned. u may have a 
look: qsl.net/dj8wx/00010.html, picture "messung.jpg" (possi u can not see it, 
if u use an other browser than internet explorer because my html-writing is not 
as good as it should be!).
BTW. ..... DON`T stand on the plate .......:
don`t stand on the radials too! whilst I keyed the tx outomatically measuring 
the fieldstrength outdoors far from the antenna I observed my chickens in the 
garden doing some uncontrolled somersaults.
I do not use the T-antenna anymore. qso`s with OH were not possi. nowadays I got 
LWs of C-shortened lambd/4 length erected and qso with OH is no broblem anymore.

regards
Uwe/dj8wx