[Waverley ARS] Isotron Antennas Pros & Cons

[Jonathan Kelly]

FWIW...

I got curious myself about this and did some research.

Dave Cuthbert did some extensive testing of the isotron in the AntenneX 
on line magazine(http://www.antennex.com)

(Unfortunately you have to subscribe to get access to the articles, I 
reckon is worth it but you would have to decide if it is your thing)

For subscribers:
http://www.antennex.com/archival/archive5/Oct02/Oct602/isotron.pdf for 
the isotron article.  (He has another article about it which goes into 
more maths and analysis)

He does a lot of mathematical analysis and modeling and then actual 
testing on the antenna.

In summary from the articles the antenna has been around for over 20 
years and he found that it does work - not a great performer compared to 
a conventional antenna (eg a 1/4 wave vertical) but he concludes it 
could be useful in tight spaces then goes on to explore how to make it 
work better (with the idea that you use it as a model to make your own 
and experiment).  The antenna installed as per recommended method 
radiates mostly via the feedline 'earth' side and so the feedline does 
the radiating.

The construction apparently is fairly simple (it uses PVC pipe as coil 
former and aluminium sheet - no fancy parts).  You may be able to make 
one yourself and play with it.

The comment he makes in regards to another antenna I think is worth 
noting as it would apply to all antennas:

an antenna can be:
1. Small
2. Wideband
3. Efficient
... pick any 2

regards

Jon (VK2JHK)
--
Jonathan Kelly
56 Railway Parade
Annandale, NSW 2038
61 2 9555 6554