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From: pjk@hou2a.UUCP (P.KEMP)
Newsgroups: net.video
Subject: Re: Stereo confusion
Message-ID: <590@hou2a.UUCP>
Date: Mon, 19-Aug-85 11:40:06 EDT
Article-I.D.: hou2a.590
Posted: Mon Aug 19 11:40:06 1985
Date-Received: Tue, 20-Aug-85 22:02:17 EDT
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Organization: AT&T Bell Labs, Holmdel NJ
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[Sorry to continue this discussion over the net, but
there are some items that are of general interest.]

Steve, I'm sorry if I misunderstood some of your
statements on VCR AFM recording, but there still
appears to be some confusion remaining.

In VHS AFM HI-FI recording, the FM modulated audio
signals are recorded in a frequency band where there
is still substantial video signal energy.  That is
why "Depth-Multiplexing" is used.  The AFM signal
penetrates deeper into the tape because the AFM heads
have wider gaps than the video heads.  The wider gaps
do not pose a problem because of the lower frequencies
of the AFM carriers.  This, along with head azimuth
offset, minimizes the interference between the AFM and
video signals.

I can't believe that the new, top-of-the-line,
Panasonic 1740 can't PLAY Dolby stereo linear
audio, but Steve is correct!

The review of the 1740 in the September issue of
VIDEO Magazine states in the last paragraph:
>  Note: if you want linear-track stereo, buy last
>  year's models now.  Almost all VHS manufacturers
>  are switching from stereo to a mono linear track.

I guess I'll keep my Quasar 5845 VHS HI-FI for awhile.
It can both RECORD and PLAY the linear audio tracks
in Dolby stereo.

As far as "enhanced" VHS from JVC goes, Steve
Lionel boasted in his original posting:

> Well, that's our history lesson for today.  Perhaps in a year or so, we'll
> see if JVC MANAGES TO COME UP WITH SOMETHING *APPROXIMATING* Superbeta.  From
> recent announcements, it doesn't seem that way.

Well, I think that "enhanced" VHS from JVC is something
approximating SuperBETA.  While it doesn't actually increase
the video frequency response by much, it does make the
picture *appear* sharper.  This along with the video noise
reduction technique that JVC is now working on, should result
in better quality VHS pictures in the future.

Does anyone know if tapes recorded with "enhanced" VHS
will appear sharper played back with a regular VCR?
Since it works as a pre-emphasis, I think it would.

I personally feel that the BETA system is technically
superior to the VHS system, but unless your video system
can exist independent of the outside world (or you happen
to have friends and video stores nearby that have BETA),
you are better off with VHS because of its overwhelming
popularity now.  Sony is now the only VCR manufacturer
that produces only BETA home VCRs, and they are placing
their bets on 8mm as the format of the future.

-- 
			Paul Kemp
			ihnp4!hou2a!pjk