QRP Voice Powered Transmitters - CW and Speech!

[Andre Kesteloot]

Ahhh, the good old Western electric 500 :-)
André


On 3/15/2013 16:40 PM, Phil wrote:
> My primary school had a new canteen and hall with a 200 foot iron fence around it in a U-shape. We used to send coded messages from one end to the other by tapping the rail with keys. Mind you, battery-free transmitters - I'm still trying to grasp it. I particularly like the way the full-wave rectification doubles the voice pitch. Move over, chipmunks!
>
> Next challenge - 100% battery-free radio DX contest?
>
> Phil M1GWZ
>
>
> On 15 Mar 2013, at 02:23, Joseph Bento wrote:
>
>> Richard,
>>
>> I was about that age when I discovered that the ear pieces from a Western Electric 500 telephone needed no power source to produce a 'telephone'.  I had two ear pieces and connected them together.  I then reconnected them via a 100 foot extension cord.  I had made a sound-powered telephone, and I didn't even (yet) know what that was.
>>
>> Joe, N6DGY
>>
>>

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