AVR-Chat

Hi Hein,

I guess I should have clarified "for any distance".  Yes, you can generate 
a signal with a few transistors and couple it to a small wire with a 
capacitor but you're only going to get a few hundrerd feet at most with 
it.  That's why I wondered what it's to be used for and over what 
distance.

I guess I'm thinking like a lowfer, where we're trying to get signals 
hundreds of miles on 136 kHz. That can't be done without coils somewhere. 
Either that or very large pieces of real estate that most of us don't 
have.  :-)

Zack

On Tue, 1 May 2007, kernels_nz wrote:

> Hi Zack,
> 
> Cant say I fully agree, I cant recall the exact detail, but I have
> built a voice-AM transmitter without any coils, I went something like:
> 
> Buy a 4-pin crystal oscillator outputting square waves at the
> frequency of carrier your looking for, I believe mine was 1MHz, then
> vary the supply voltage depending on the "voice" input voltage.
> 
> Cheers
> Hein B
> Auckland, NZ
> 
> --- In AVR-Chat@yahoogroups.com, Zack Widup <w9sz@...> wrote:
> >
> > 
> > It can't be done. You will need a coil at least for your
> antenna/matching.
> > 
> > How much power are you talking about?  What range do you want to cover? 
> > For what purpose?  What frequency?  What are the laws in your country 
> > regarding license-free transmissions on that frequency?
> > 
> > Inquiring minds want to know, especially this RF engineer.
> > 
> > Zack
> > 
> > On Wed, 25 Apr 2007, azza eldessoky wrote:
> > 
> > > please friends,can any one  send me a circuit design for AM
> transmitter or receiver without  any coils .
> > >    thanks alot 
> > >        azza 
> > >
> >
> 
> 
>