Re: 150Khz Antenna question

On Wed, 02 Jul 2008 14:29:23 GMT, "Jacques St-Pierre"
<multelec@[EMAIL PROTECTED]
> wrote:

>Anyone can help me with the design of a compact 150Khz antenna?
>
>Let me explain the goal, I need a way to induce a 150Khz signal to a 
>compound for an experiment.
>
>I will build a supply using a LM555 at 13.8Vdc and a transformer to
produce 
>a 150Khz square wave of 140Vp-p approx.
>
>I need to couple that 150Khz signal to a sort of compact antenna to 
>emit/induce the wave to the compound. The coil should be compact enough
to 
>be insert in a plastic case of 2" x 4" inches.
>
>What is the best length of wire to use? What is the best way to wound it?

Search Google for "LowFER".  These are radio stations in the 136KHz
region.  Much of the technology should be directly applicable.
<http://en.wikipedia.org/wiki/LowFER>

Please note that attaching an antenna to your 150KHz square wave trash
generator is a bit like constructing a jamming transmitter, with
harmonics extending well into commercial and broadcast frequencies.  I
suggest you make an effort to limit your harmonics by using a sine
wave, not a square wave.


-- 
Jeff Liebermann     jeffl@[EMAIL PROTECTED]
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