Using DVD players with older sets

[AUdubon5425]

Hi everybody,

My DVD player died, and I plan to purchase a DVD recorder so I can dub many of my recorded VHS tapes that are starting to degrade.

My plans are to eventually replace the 27" Durabrand TV in the den with a color console set from the 60's or 70's.

I remember having trouble watching some VHS tapes on my '75 Quasar - the picture would bend at the top of the screen. From what I understand, I should not have picture quality problems if I run a DVD player through an RF modulator. Can anyone confirm this?

Also, although I have a Philips VCR that I'm quite happy with, I am thinking about buying a VCR/DVD recorder combo to avoid those picture quality issues.
Is there any particular brand I should avoid? I haven't heard anything one way or the other on the quality of these combo units.

Thanks,

Ryan

[steerpike2]

I think the picture tearing (is that spelled right??) is due to the synch pulse instability/variability on VHS recorders; TV sets can be modified to accommodate this though. DVD players have a much more stable timebase, so wont do this. But the VHS part of a DVD/VCR combo will still have the same issue a a stand-alone VHS machine in this area.

The Macrovision spoiler in a DVD player output may upset some TV sets though. You can buy or make filters that fix this problem.

I use a DVD player on a 1984 Philips set via RF modulator with no picture problems; the DVD audio via the TV set is buzzy, but its not a problem since usually you'd use an external hi-fi amp for sound.

[zenith2134]

FYI, a lot of older VHS decks will defeat the macrovision when a DVD player is piped through their composite video inputs. Pre-1985 I'm thinking.

[dtuomi]

The waving at the top of the screen is called flagging. Its a common problem when time base errors inherent in the tape overcome the receiver's ability to lock onto the sync.

Macrovision is basically a technique of messing with the AGC circuits in a recording deck. It is inserted outside the normal picture region in the upper scan lines of the picture. Basically its a pulsing set of lines that go from 0% (blacker than black) all the way up to 120% (over modulated white). Those percentages are in IRE values.

The solution for all these problems is to get a full frame time base corrector. Its a device used in TV stations to allow helical scan VTR's to be able to be used with live cameras and other stable sources.

The time base corrector will eliminate flagging in the picture. The better one's will also strip the sync and insert a fresh one (without copyguard annoyances).

They're a little pricey for new ones (around $400 for a low end model). But, they're common enough on ebay. If you go for a used one, get a newer one and be sure its full frame, they did make them that only corrected so many lines (memory used to be real expensive), and those won't do anything for Macrovision.

You probably would only need one of them, plugged into your RF modulator for your set.

David