den@hpficad.HP.COM (Don Novy) (01/06/89)
I am looking for a converter box for a frame grabber I am building. I need
to convert cable TV video (most likely channel 3) to composite video
(NTSC baseband). Does anyone know of such a converter? If so, who makes it
and how much does it cost?
Let me offer a few more words of explanation for this. The VCR I own does
have a composite video output but the sync pulses are not very good. I have
been working on a stable sync separator circuit for months without luck. After
examining the composite video signal inside my TV, I learned that the sync
pulses from the VCR were pretty bad. I would prefer not having the VCR
generate a channel 3 signal and then drop it back to baseband, but the TV
picture from the VCR is fine so I'm sure this will work.
Thanks in advance for any help,
Don Novy
Hewlett-Packard CICD
(303)-229-3211craig@hp-lsd.HP.COM (Craig McCluskey) (01/07/89)
> I am looking for a converter box for a frame grabber I am building. I need > to convert cable TV video (most likely channel 3) to composite video (NTSC > baseband). Does anyone know of such a converter? If so, who makes it and > how much does it cost? Why not use the guts of a cheap TV set? Craig McCluskey HP Logic Systems Division Colorado Springs, CO ...!hplabs!hp-lsd!craig
jim@trsvax.UUCP (01/07/89)
Several of the remote control boxes for older TVs (remember when they
didn't come with remotes? 8{) use a tuner to convert the signal to
NTSC. I'm not sure ALL boxes do this, but i think all the ones with
volume control (up/down/mute) do. This should allow you to tune all
of the band (VHF/UHF/Cable) and let you see what you are REALLY
looking at on the RF output with a cheapo TV. Good luck!
James T. Wyatt UUCP:decvax!microsoft!trsvax!rwsys!jim KA5VJLjim@trsvax.UUCP (01/10/89)
hp-lsd.UUCP!craig writes in sci.electronics:
" Why not use the guts of a cheap TV set?
Be REALLY careful with cheap TV sets. A lot of them have saved
manufacturing costs by using a ploarized plug and NO ISOLATION
TRANSFORMER. They just rectify the AC and use a dropping circuit
to get the various B+ voltages. This can cause lots of smoke when
connecting the internal stuff from the TV to the internal stuff of
your computer. I lost some chips in my 'ol TVT-II from Popular
Electronics a few years ago doing this - then I went to Software! 8{)
James T. Wyatt UUCP:microsoft!trsvax!rwsys!jim KA5VJLjohng@trwind.UUCP (John Greene) (01/10/89)
In article <7600018@hp-lsd.HP.COM> craig@hp-lsd.HP.COM (Craig McCluskey) writes: > >> I am looking for a converter box for a frame grabber I am building. I need >> to convert cable TV video (most likely channel 3) to composite video (NTSC >> baseband). Does anyone know of such a converter? If so, who makes it and >> how much does it cost? > >Why not use the guts of a cheap TV set? > A few years ago we had the need for both RF modulators and demodulators for a video intercom system. The systems also used time lapse VCRs which were a modified commercial VCR. The company that made them would strip all of the unnecessary components out of the unit to make room for the time lapse stuff. They then sold us the modulators and demodulators for about $5-10 apiece. The modulators being much less than the demodulators. It has been over four years and I don't remember the name of the company but you can check for a similar one in you area. -- John E. Greene "People are just like frankfurters....You have to decide if you're going to be a hot dog or just another wiener" DLR TRW Information Networks Division 23800 Hawthorne Blvd, Torrance CA 90505 ARPA: johng@trwind.ind.TRW.COM USENET: ..trwrb!trwind!johng