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Message-ID: <000d01c69b51$fc13f360$1f03210a@Hugh>
From: "Hugh_m0wye" <m0wye@radiouk.com>
To: <rsgb_lf_group@blacksheep.org>
References: <200606280505.k5S55B38054415@dslgw1.aebc.com> <44A3145C.9020702@ukonline.co.uk>
Date: Thu, 29 Jun 2006 08:59:39 +0100
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Subject: Re: LF: LF/HF/VHF Spark?!
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Status: O

Hi All,
Lack of interference form Tesla coils...

Thinking about it from a "conservation of energy" point of view, most of the 
energy must be going into producing heat, light and sound, and ripping 
molecules apart to make ozone. So only a fraction of the 3kVA can be being 
converted to EM waves.

If you have a "one meter spark" as an antenna, it is not really that 
different to having a 1 meter loop antenna, as long as there are not other 
long cables acting as radiators. We wouldn't think of a 1m loop antenna as a 
very efficient TX aerial at LF ... VHF maybe.

At LF frequencies one would might be in the near field which might have a 
bearing on what was received when looking for interference.

73
Hugh M0WYE

----- Original Message ----- 
From: "Peter Dodd" <g3ldo@ukonline.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Thursday, June 29, 2006 12:44 AM
Subject: Re: LF: LF/HF/VHF Spark?!


> Martin Mac Gregor wrote:
>
>>
>>The point of this saga...
>>
>>Latterly we discovered that Industry Canada (DOC) had too become involved 
>>on
>>an investigative basis; we learned that during our exhibitions, local
>>broadcasting and even low band TV in the immediate locale was reportedly
>>obliterated but certainly interfered with.
>>
> One weekend, during the early experiments on 136kHz from Amberley museum, 
> we had a group come and give a demonstration of Tesla coils. I set up a 
> mobile receiving station that had the ablility to tune from 70 to 180kHz 
> (the fundemental frequencies of these coils) to see how strong the 
> electromagnetic radiation from these coils would be. I couldn't receive 
> anything, even when the mobile receiver was located 200m from a coil 
> giving off a one metre length spark. I don't think the receiver setup was 
> that deaf because I could hear the usual commercial and broadcast stations 
> in the band. These results certainly surprised me - perhaps I should have 
> looked in the VHF bands.
>
> Peter, G3LDO
>