AK <00@case.edu> writes:
> Martin, I built what you are looking for back about 12 years ago using
> optical methods. Using an analog to TOSLINK converter (I have extras if=20
> you
> are interested), I modulated a laser instead of the LED in the TOSLINK
> connector, and sent the audio over free space to a receiver.  The sound
> quality was perfect (no loss of highs I have experienced from transformer
> isolators) and fun. You would just need to find a piece of equipment with
> TOSLINK input.

	This is exactly why I asked this question as I had no
idea what might come up.

	I actually have some devices that have Toslink outputs
and inputs.  One is a Behringer usb sound card which is aimed at
musicians.  It has no mic input but 2 line-level RCA phono jacks,
a headphone jack and a Toslink optical output that speaks SPDIF.
I also bought a rebuilt CD audio recorder back in the late
nineties that sports both a Toslink input and an output.

	I didn't know much about Toslink up to this very moment so
I looked it up.

	It is absolute overkill for the audio of that general
coverage short wave receiver, but all I really need do is to buy
a Toslink cable long enough to reach where the CAT 3 cable is
now and see what happens.  The Toslink cables appear
to come in a connector style that looks somewhat like a 3.7 MM
headphone jack and some use a square socket and there may be
adaptors to hold one of the round plugs in that square opening.

	That would give two good-quality audio channels and all I
don't have is the cable so the project has almost assembled itself.

	If I find out that the encoder generates yet more RF
noise, I'll have to solve that problem but the Toslink system
seems very promising.

Thanks very much.

Oh yes.  That usb sound card is aimed at musicians but I never
got good enough to be called one.  The sound card works great for
recording audio from scanner radios and any other unbalanced line-level
source.

Martin McCormick WB5AGZ
--=20
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