🚀 go-pugleaf

In article <4561@polari.UUCP> mzenier@polari.UUCP (Mark Zenier) writes:

[some discussion of MTS stereo TV sound deleted]

>>So how does it work, and does
>>anyone have any chips to do this? Has Radio Electronics done this yet?

>Yes again, about 4 or 5 years ago.  One trick is that some of the signal
>(the L-R ?) is processed through some sort of Dolby noise recduction that
>is patented, which the RE project did not do.

>Mark Zenier  markz@ssc.uucp  mzenier@polari.uucp

Actually it is dbx.  Similar to dbx cassette players.

The reason radio electronics did not include the dbx noise reduction is
that it would be illegal, I think.  I don't know the details, but dbx
equipement must be licenced with the designers and manufacturers of dbx. 
You can get a licence, but then all you can do is buy dbx decoding chips
and put them in your equipment.  You can not sell the parts to the general
public for their own use.  Therefore there would be no way of the general
public to get the dbx decoder parts, even if they did include it in the
project.

They did include some replacement circuitry that came close to performing
the function of the dbx chips, but it wasn't near perfect.  If they did
include an exact replacement circuit for the dbx parts, they would probably
be in trouble for patent infringements.

So the only way to get TRUE MTS stereo TV is to buy a stereo TV or an and
on stereo decoder box.

BUT, if all you have is a poor sounding mono TV, the Radio Electronics 
project will still sound FAR better, even if it does not have the dbx
circuitry and is not true MTS stereo.  It is likely that most people 
will not hear the difference, and the ones that do won't hear much of
a difference.

It's hardly worth the trouble to build this project, since you can get a
Recoton FRED III Stereo MTS decoder box from Damark Inc, for $39.99.  It
will either demodulate channel 3 audio, use the MPX output of your TV, if
it has one, or will pick up the audio IF with a probe that you stick on
the bottom of your TV.  It will receive true dbx MTS stereo, SAP (second
audio program), and has a 12 watt audio amp built in.   You couldn't buy
the parts for this and build it yourself for less than $39.99.

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Carl D. Smith Jr.
csmith@plains.nodak.edu
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