From: brown@vidiot.UUCP (Vidiot)
Newsgroups: rec.video.cable-tv
Subject: Re: CATV Operator Dropping MTS Signal
Date: 6 Jan 93 05:22:40 GMT
Reply-To: brown@vidiot.UUCP (Vidiot)
Organization: Vidiot's Hangout

In article <2935249429@ARTEMIS.cam.nist.gov> miller@FS1.cam.nist.gov (Bruce R. Miller) writes:
<
<In article <1993Jan4.152119.24886@rtsg.mot.com>, Robert P. Heape writes:
<> Here in Chicagoland, my cable operator drops the MTS Encoded
<> Stereo signal for the public channels (ABC/NBC/CBS etc.).
<
<Hmm, that's surprising.  Do _any_ channels (eg. from satellite) come in
<stereo?

Yes, pretty much all of them.

<When I found that even Cinemax (which we're getting for a `free' sample
<month) didn't come in in stereo,  a plausible model occured to me.

Because your cable company didn't spend the money to get MTS capable equipment.

<_All_ our local stations come in on stereo, _none_ of the cable stations
<do.  I'm assuming that whatever means our cableco uses to get the
<signals for the local stations (apparently not directly over the air, at
<least I've never noticed bad signal from weather) involves only minimal,
<straightforward modulation.  Then the mts sideband (or whatever you want
<to call it) gets carried along and de/re-modulated `for free', without the 
<cableco having to do anything extra to send it out to us.
<  The stations coming in from satellite presumably have a more involved
<modulation/encoding so that the cable co has to make a concious effort
<(and investment!) to decode the stereo and insert the mts signal.
<In which case, they haven't.
<
<[Yo experts; Is this a reasonable model of what goes on ?]

No.  In order to have local MTS stereo, the connection must be via over-
the-air with a wideband receiver/transmitter or direct feed.  The over-the-
air wideband receiver/transmitter is a unit that receives a certain channel,
coverts to IF and the converts again to the required channel.  It is a full
bandwidth receiver.  In the case of the original poster, the cable company
may have used an over-the-air receiver that goes to baseband video and audio,
which will result in the loss of stereo when remodulated to the new channel.
The other method (used in this city for three of the 5 channels), uses a
special FM, very wideband, long distant transmitter.  This is used to send
a MTS encoded video/audio signal from the TV station, to the cable company,
via cable, to a special receiver that reduces it to the proper cable channel.
Stero encoding, etc., are all controlled by the TV station.

Satellite received signals for cable, are basically all using the Video
Cipher scrambling system.  This system uses digital stereo audio.  At the
cable head end, the professional VC decoder provides video, left channel,
right channel and mono audio.

<I asked the cableco, who said they would need to add more equipment and
<it was a relatively low priority item for them at this time.  Apparently
<few people do complain about it.  How much does it cost to `upgrade' a
<channel's satellite reciever to decode & retransmit the stereo?

It costs about $2,000 to take a cable channel modulator and upgrade it for
MTS stereo.  That is why our cable company isn't doing it either.  We get
HBO, MTV, TNN and Showtime on FM stereo.  Our company is also going through
a complete rebuild.  At that time all of the headend transmitters will be
replaced, supposidly with MTS capable equipment.  No need to spend the money
twice.
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