[Laser] Re: RTTY over light, anyone tried it?

[Art]

I've never done any form of listening, except for weak signals using 
FFT and looking for the signature frequency using spectrum Lab.

But, I notice quite a few are using soundcards for various modes, 
some for weak signals, some for moderately loud signal modes.

One topic that seems to be missing in this (and other threads) is the 
soundcards input noise level. All soundcards are not created equal 
and some are just barely worthy of playing the windows sounds when 
the computer boots up.

The SDR, softrock and Flex-Radio people have done extensive research 
into soundcards and the differences between the noise associated with 
the input of the soundcard varies widely.

Anyone who is doing weak signal work with soundcards should be wary 
of the AC97 integrated sound card chip set, which is absolutely 
horrible. Sound Blaster sound cards claim 24 bit sampling, but the 
first 10 bits are totally dominated by noise built into the card 
itself, so it is no better than a 16 bit soundcard due to Mickey 
Mouse electronics used on the card itself.

The best 24 bit soundcards are pricey and perhaps don't fit within 
most laser users budgets. But, there are a few models that work 
extremely well and are not expensive.

Other issues that degrade the performance for weak signal modes are 
the lack of a balanced input (ground loop problems) which are a 
significant issue that many seem to be totally unaware of.

Keep dem laser lit and enjoy. But, do be aware that what you do not 
know about your soundcard can hurt you.

Regards,

Art