[sci.electronics] NTSC->Composite

othomas@athena.mit.edu (Oliver J. Thomas) (06/18/91)

Hi.Does anyone have plans for an NTSC to composite converter? I would need
something that takes coax VHF output from a Cable box and converts it to a
composite video and audio signal. Sort of a VCR without the..well..VCR.
Perhaps Radio Electronics ran something like this?

	Thanks for any pointers,

		Oliver

myers@hpfcrlm.HP.COM (Bob Myers) (06/19/91)

>Hi.Does anyone have plans for an NTSC to composite converter? I would need
>something that takes coax VHF output from a Cable box and converts it to a
>composite video and audio signal. Sort of a VCR without the..well..VCR.
>Perhaps Radio Electronics ran something like this?

"Composite video and audio" IS baseband NTSC.  What you're looking for is
something that takes the NTSC-modulated signal on channel 3 or 4 coming out
of the VCR/cable box and converts it to baseband - in other words, a tuner.  
Tuners are available all over da place - you can pick 'em up from the surplus 
stores for a song (and maybe a dance or two, depending on the quality of your 
singing).  Feed a solid-state tuner a little bit of the right voltage(s),
and you'll be able to pick the video and audio right off (usually from separate
jacks - or did you want to leave the audio in the video signal?).



Bob Myers  KC0EW   HP Graphics Tech. Div.|  Opinions expressed here are not
                   Ft. Collins, Colorado |  those of my employer or any other
myers@fc.hp.com                          |  sentient life-form on this planet.

mwandel@bnr-rsc.UUCP (Markus Wandel) (06/20/91)

In article <OTHOMAS.91Jun18121556@e40-008-11.mit.edu> othomas@athena.mit.edu (Oliver J. Thomas) writes:
>
>Hi.Does anyone have plans for an NTSC to composite converter? I would need
>something that takes coax VHF output from a Cable box and converts it to a
>composite video and audio signal. Sort of a VCR without the..well..VCR.
>Perhaps Radio Electronics ran something like this?
>

As someone already pointed out, you need a TV tuner.  The stuff that comes out
of the cable is not NTSC, but the "composite video" is.

The most convenient thing to do is to get a cable box with direct audio and
video outputs.  These seem to be present on most of the cable boxes with
volume controls on the remote, probably because to implement the volume 
control, sufficient decoding is necessary to make these signals available
for free.  Attach this to the monitor left over from your old 8-bit
40-column computer (C64/1702 monitor in my case) and get a GREAT TV!
Expect to pay about 1.5 times as much for a volume control cable box as for
one without a volume control.

Myself, I use a "VCR without the... well... VCR".  It's the tuner half of a
portable VCR/stationary tuner combo from before the camcorder days.  Got it 
the tuner half only) cheap in a surplus store.

Markus Wandel

mzenier@polari.UUCP (Mark Zenier) (06/21/91)

In article <OTHOMAS.91Jun18121556@e40-008-11.mit.edu> othomas@athena.mit.edu (Oliver J. Thomas) writes:
>
>Hi.Does anyone have plans for an NTSC to composite converter? I would need
>something that takes coax VHF output from a Cable box and converts it to a
>composite video and audio signal. Sort of a VCR without the..well..VCR.
>Perhaps Radio Electronics ran something like this?

Er, composite is NTSC.  If you want a seperate tuner, DAK was selling 
them last I looked.  One even had a built in stereo decoder.


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