Searching \ for 'OT VIDEO SYNC' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/displays.htm?key=video
Search entire site for: 'OT VIDEO SYNC'.

Truncated match.
PICList Thread
'OT VIDEO SYNC'
1997\09\18@093105 by GERALD LEWIS

flavicon
face
    I want to use a VCR to record audio only.  However, the audio track
    will not record unless a baseband video signal is present. It does not
    have to be modulated.  Does anyone know of a source for a portable
    baseband sync generator.  I do not have the time to build one.

       Tnx.  Gerald Lewis

1997\09\18@115406 by scaexpert

picon face
GERALD LEWIS wrote:
>
>      I want to use a VCR to record audio only.  However, the audio track
>      will not record unless a baseband video signal is present. It does not
>      have to be modulated.  Does anyone know of a source for a portable
>      baseband sync generator.  I do not have the time to build one.
>
>         Tnx.  Gerald Lewis
Yes, I do know of a source for a portable baseband sync generator that
will serve your purpose...It's called CABLEVISION or ANTENNA...and
tuning in an active signal in your area...and setting your VCR in
LINE/EXT AUDIO.
Good Luck

1997\09\18@131353 by Mike Keitz

picon face
On Thu, 18 Sep 1997 08:07:52 -0500 GERALD LEWIS
<spam_OUTGERALD_LEWISTakeThisOuTspamNSDGATE3.NSD.FMC.COM> writes:
>     I want to use a VCR to record audio only.  However, the audio
>track
>     will not record unless a baseband video signal is present. It
>does not
>     have to be modulated.  Does anyone know of a source for a
>portable
>     baseband sync generator.  I do not have the time to build one.
>
>        Tnx.  Gerald Lewis
>
Most VCR's of the "hi-fi" (not "HQ") type have a circuit which allows
them to record audio only.  Of course you want to use a hi-fi VCR anyway
since the audio quality is much higher.  The one I have also has a switch
that lets you take video from the tuner and audio from the line inputs.
So you could tune in a strong TV station for the video reference.  VCRs
that don't have a "Input : Tuner/Line" switch on the panel usually have
the switch in the input jacks.  When a plug is inserted, the tuner is
switched off and the line input becomes active.  Possibly just plugging
in the audio cable but not the video will let you use video from a TV
station along with external audio.

Exhausting these possibilites, the quickest way to improvise a sync
generator from mass-market items would be an inexpensive CCD camera and
some black tape (for the lens).

As for hommemade there is an old RCA CMOS chip designed to do exactly
this but it is somewhat expensive.  It would also be a not too
complicated PIC project.  The NTSC horizontal rate is 4.5 MHz / 286.
This video signal would be somewhat nonstandard since you'd be using the
color frequency but not transmitting any color bursts.  This is how many
B&W movies were broadcast (back when there was such a notion as
broadcasting a B&W movie) so VCR's should accept it.

Unfortuantely 286 / 4 = 71.5 so a 9 or 18 MHz PIC crystal would be needed
to make the frequency come out to an integer number of PIC instructions.
The 18 MHz frequency seems to be most readily available, but it is too
fast for a 16X84.  Of course a VCR would lock to frequencies that are a
little off so uisng whatever crystal you have and the closest integer
would likely do.

1997\09\18@153340 by Steven J Tucker

flavicon
face
On Thu, 18 Sep 1997, GERALD LEWIS wrote:

>      I want to use a VCR to record audio only.  However, the audio track
>      will not record unless a baseband video signal is present. It does not
>      have to be modulated.  Does anyone know of a source for a portable
>      baseband sync generator.  I do not have the time to build one.

Have you tried just plugging VIDEO OUT into VIDEO IN? ;)  There must be
a baseband generator already running in the VCR somewhere, if its turned
off you just need to find the signal.

Steve

1997\09\24@110922 by Martin McCormick
flavicon
face
Steven J Tucker writes:
>Have you tried just plugging VIDEO OUT into VIDEO IN? ;)  There must be
> a baseband generator already running in the VCR somewhere, if its turned
> off you just need to find the signal.

       I record audio all the time through an old Panasonic PV1225 VCR
of about 1984 vintage.  There is no sync at all at the video output jacks
in the absence of signal.  The audio inputs have nothing to do with the
video so it is perfectly possible to use an antenna or cable source for
a signal and use that source for sync.

       Another signal source might be a video game box.  All it has to do
is generate NTSC video and you should be all set.

Martin McCormick

More... (looser matching)
- Last day of these posts
- In 1997 , 1998 only
- Today
- New search...