ph28kc@sdcc12.UUCP (ph28kc) (03/07/85)
I want to run the composite output of my IBM color graphics card directly into a Sony Betamax video tape recorder. It seems that all I'll need is an RF converter whose output I'll run into the antenna/cable input of the VCR. It seems too simple to really work and so, before plopping down my money for an RF converter, Id like to see if anybody has any knowledge, opinions, or experience reguarding such a hookup. iSpecifically: -Do you think this scheme will work ? -If so, do you recommend any particular RF converter or source for them.? -What about the Video inputs onthe recorder? could they be used in some manner that wouldn't require the RF converter? Please respond via Mail - I'll summarize if there's interest Thanks in advance - Ken Cluff -- Ken Cluff ucbvax!sdcsvax!sdcc3!sdcc12!ph28kc
vch@rruxo.UUCP (V. Hatem) (03/11/85)
I'm not shure what your budget looks like, but for about $2500 or so you could have a device that I found very helpful. It will translate RGB analog, RGB TTL, or video into a form that a specialized video monitor can use. Both the translator (called a switcher, because it can take up to 10 inputs) and the projector (about $20K) are distributed by a place called INFLIGHT SERVICES Inc.. They are somewhere in Manhattan. We use it mainly for presentations and training classes. It is actually readable at 132 chars! (many aren't at 80). I forgot to mention - the switcher can output whatever it inputs. ie: if you want video output - you got it. no matter what the input was. good luck. Vince Hatem Bell Communications Research rruxo!vch
dtynan@cadvax (Dermot Tynan) (03/19/85)
Disclaimer: I have never tried to do the hookup you suggest, but can offer
some useful information.
For one, if you have a composite video input on you VCR, you don't need an RF
converter. You can take the direct video from the system, to the VCR. This
gives a better signal than using a $5 RF converter, as those things have real
"el cheapo" RF oscillators. I know that on my VCR, there is a composite input
and output, for both video and audio. There are two phono sockets at the
back, for audio and video output, and two on the front for input. From what
I'm told, VCR's use a mechanical sync. (Yeugh!!!), whereby the rotating heads
are actually in sync. with the incoming signal. TV stations keep their sync
signal *precise*, so once the VCR locks in, it will hold. Unfortunately,
a lot of personal computers use el cheapo sync. circuitry as well, thus the
VCR *may* have trouble staying in sync with the computer. This problem arises
with either a direct-connect, or an RF converter -- be warned. It shows up
characteristically, as screen-roll (loss of vertical sync), or as a screen
with diagonal bars (I don't know what the tech term for this is, but it's
caused by loss of horizontal sync). As a matter of interest (or trivia), most
video protection schemes involve a slight variation in the sync field, which
(supposedly) screws up the recording on a second VCR. It can also show up
as "interference" on the playback VCR, hence the protection scheme is normally
injected at the beginning, during the credits. Anyway, back to your question:
I would suggest a direct hookup, and watch out for bad sync. If you do get a
poor picture from the VCR, I wouldn't dash out and buy an RF converter, as it
won't help your problem, you'll just have to wait until they start digitizing
VCR's. I hope this is some help...
- Der Tynan
PS: Excuse the posting, but I couldn't send mail...
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