Re: LF: VK1OD's analysis of the MiniWhip antenna

[Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>]

Am 06.07.2013 20:32, schrieb Roelof Bakker:
> [...]However this is irrelevant as the output is easily adjusted by 
> adapting the size of PCB antenna.
That sounds so easy but unfortunately we have to fight with DCF-39 here 
:-( There are certain countries where it IS so easy :-)
> The feed line is not part of the antenna.
What is then the counterpoise of the whip? The second plate of the 
capacitor? Where does the potential difference come from? It must be the 
metallic structure connected to ground (GND in the circuitry) and 
connected feed line, either coax or twisted pair or what ever.
> One test I still intend to do is to feed the antenna with a 9V battery 
> and use fiber optic to transport the rf to the shack. I am using a non 
> conductive fiber glass pole and my guess is that the antenna still 
> will work.
I agree. But it will have a counterpoise too, e.g. the plates inside the 
9V battery.
If the whip electrode connected to the FET is a tin can and the complete 
circuitry including the battery is inside that box, only a small hole to 
feed out the fiber optic cable, then the voltage or signal will be 0  
(or just noise).
73, Stefan/DK7FC

> 73,
> Roelof bakker, pa0rdt