NEC-LIST:Modelling of a radiating coaxial "probe"

Hello All

I am wondering if anybody could give me some pointers on modelling a
coaxial "probe" I am using. It is just a piece of RG58 coax 170mm
(6.69in) long, but with the outer insulation and shield stripped back by
20mm (0.79in) exposing the dielectric, which is left intact. The shield
is connected to ground. I am using it in two different scenarios,
connected to a transmitter and also to a receiver.

I am using EZNEC v.3 and have looked at the information in its manual.
The suggested technique is to use a transmission line for the centre
conductor and a wire for the outer conductor, unfortunately I do not
think you can extend the TL past the end of the wire, although the
overall length of the TL can be longer, so negating its use here. Also
I believe that TLs are non-radiating. If I am wrong here, please
correct me.

My other thought was to create a mesh of wires in a cylinder and one
wire down the centre. The cylinder representing the screen, the central
wire being the centre conductor.

If anybody has any advice, or thoughts, then it would be most
appreciated, and if I have totally misunderstood things then please feel
free to correct me. I must admit I am not a power user of NEC and so
need a little shove in the right direction every now-and-again!

Thanks all for any help.

Russell.

-- 
Russell Iain Macpherson
Electromagnetics Research Group, Department of Engineering
University of Aberdeen, Scotland, UK.
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