[Laser] First test of sending data via fluorescent or High Pressure Sodiu...

[Kerry Banke]

Yves - Thanks for the info on Jason. I have been meaning to try it 
but haven't done so. Now seems like a good time to give it a try. I 
agree being close to 120 Hz will no doubt be a concern. I found I can 
easily power the lights ok  up to beyond  70 Hz so I may move up to 
say 130-140 Hz or higher modulation .  So far I am using the original 
ballast for the lamps which I'm sure is limiting the frequency 
operating range. If this type of beacon proves to be of interest, I 
may try building my own lamp driver that will not be frequency 
limited to near 60 Hz.  I also want to look at the depth of 
modulation for both lamp types and see if a special driver with more 
off time might give greater modulation depth.
  - Kerry N6IZW -


At 12:38 PM 9/5/2006, you wrote:
>
>Kerry
>Very  good work with your beacon.
>As you divide the frequency by two to compensate  the "two light bursts for
>one cycle", Laserscatter is the good program  because the predivide 
>option you
>can chose but Lasercatter  needs very good audio cards quality (frequency
>accuracy)
>The 62.5-67.5  Hz range seems very close to the 60 Hz mains that gives a
>strong 120 Hz  line 5 Hz to 15 Hz near your optical signal.
>It could be a  problem at low level ?
>JASON can be also used with your "by two divider" with  the right F for TX
>frequency.
>The JASON  frequency shift will be divided by two by your divider but will be
>multiply  by two by the lamp. The beacon message must be included between the
>characters {  }.
>With this pattern JASON will send continuously the same message as long  you
>like.
>JASON works  well again with very common audio card or low cost USB sound
>adaptor with  more than 1 Hz frequency error at 100 Hz.
>Have good experiments.
>73 Yves
>
>
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