[Laser] laser product detection

[moi vaan]

Yesterday evening I got idea to some kind of light/subcarrier mixer.
I made program for mchip pic, it gives 15 KHz output to ir-led. Then I
programmed 2 chips with same software, put pics to my experimenting
board,  put  1 led / pic and listened them with my lightRX. As you can
guess, when both signal was about in balance, i heard sound, about few
hundreds herts, propably due difference in xtals. So, i changed different
xtals to second pic and got nice sidetone beats at product.

Little idea in this is  mix subcarries to sound that ear har hear they.

Now, before someone says that this is allready invented, maby, but why I
haven't heard that too many amateur is using it ?

Doesn't it then work well ? Also would it be simpler to modulate laser at tx
site and use beat osc in  light rx, making product  sound by that way ?

Or some other crazy idea, embed two carriers to light at tx site, say 19 khz
and 20 khz, ant by that way get 1 khz product sound finally ??
Of course using aproriate highpass filter, so we can eliminate 50/100 hz
buzz before we make product sound.....

Well, waiting for real comments. Send comments to laser@mailman.qth.net 
ONLY....

73 De marko
OH6JSC

bw. If such technic haven't allready done, ofcourse then copyright will be
mine ;)

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