[Waverley ARS] Isotron Antennas Pros & Cons

[Adam Carmichael]

Hi Colin and Mathias,

Trying to not go too far off topic; I think it varies largely from 
reader to reader about whether to send back to the list or back to the 
sender only. Because I reply 50/50 to the sender or to the list, I just 
hit reply-all and delete one recipient out of habit these days. It's one 
extra piece of work, but removing a recipient is almost always easier 
than typing a new one / changing an existing one.


Coming back on topic - does anyone know how these Isotron antennas work 
and what makes them tick? I see that there is a coil and two large 
plates (an open air capacitor?) so I am guessing these form a tuned 
circuit; but how does the signal actually radiate out? And just as 
important, how does a single get picked up?

I suppose that might be a secret under lock and key, or else we'd see 
hundreds of imitators now!


Regards,

73 VK2FNRD... Adam


Colin Marks wrote:
>  Hi Mathias
> Re your comment to Simon in your "PS" :
> When replying to a "members list" letter I think we often want to restrict 
> our reply to only the sender. I know this is often the case for replies I 
> send. Of course I realise this would not always be the case.
> 73    Colin    VK2LV
>
> ----- Original Message ----- 
> From: "Mathias Burbach" <mathias at maranatha-consulting.com>
> To: <members at vk2bv.org>
> Sent: Monday, March 03, 2008 6:01 PM
> Subject: Re: [Waverley ARS] Isotron Antennas Pros & Cons
>
>
>   
>> Hello Adam, Brad & Eric,
>>
>> Thanks for your replies.
>>
>> Brad wrote:
>>     
>>> Hi Mathias, I think Eric may have been referring to EH antennas when
>>> he said that.
>>> Like you, I have also been curious about these antennas.  They have
>>> been around for a long time but nobody ever mentions them.  I figure
>>> if they were really good they would be a lot more popular especially
>>> as they are so small. I thought they would be very narrow in
>>> bandwidth, but the reviews in the EHAM say differently.
>>> There are 6 pages of reviews
>>> here...http://www.eham.net/reviews/detail/311  some not very
>>> flattering and others quite positive.
>>>       
>> Yep, I had a look at those reviews and can see the very different ratings.
>>
>> Adam wrote:
>>     
>>> Are these a commercially made mag-loop? (they sure look like them) I
>>> was  thinking about building one a few months - the problem I found
>>> was getting the capacitor.
>>>       
>> No these are not magnetic loop antennas, Adam.
>>
>> Eric wrote:
>>     
>>> Hi Brad,
>>> You are spot on. Until Mathias mentioned the Isotron I had never heard
>>> of it. I have since had a look at them and they look interesting,
>>> especially the claims for them. It would be interesting to compare
>>> them with a full size dipole for each band.
>>>       
>> I have spoken to Rob (VK2VRB). He is already helping Allan (VK2VEC) with
>> his setup in the attic. Rob will come over to my place on Wednesday and
>> we will discuss possible configurations in the attic. I am interested to
>> hear what Rob has to say too. I shall also write an e-mail to David at
>> Benelec and ask if he has ever heard of Isotron antennas. I shall let
>> you know the outcome of both investigations.
>>
>> Salut,
>>  Mathias
>>
>> PS: Simon, can we setup our mail-list so that replies automatically go
>> to the list and not the sender of the message we reply to?
>>
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>>     
>
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