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  1. Does anyone know how to perform internal adjustments on a VCR to properly track old, troublesome EP tapes? I have several such tapes that I've tried in all my good VCRs, including the AG-1980, and they don't play well.

    I have several cheap Panasonic PV-9451 VCRs that I'm willing to use as guinea pigs, and I have an oscilloscope. I've also ordered some old VCR servicing books so I can learn this obscure art. However I'm interested in hearing from anyone who's done this... which subsystems would I want to be focusing on to maximize tracking quality from EP (SLP) tapes?

    If no one replies then I plan to post a how-to in a couple of months after I figure out how to do this.
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  2. Member
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    Good luck. I tried to do this recently on some interview tapes I had from 1984 on good quality Beta tapes recorded at Beta X-2 speed and failed miserably using 2 different decks (an old SL2710 and a newer SLHF860D). The older deck has a manual tracking wheel, while the later deck had buttons. Neither would adequately track that old tape. The only thing that would probably track the tape was the recorder that did the original recording. For me, that deck was junked more than 15 years ago so that isn't possible. I'm figuring that you will run into the same problems using the auto tracking in the SVHS decks you have unless you can test the tape on a number of different decks to see which ones play the tape back with the least tracking problems. Have you tried any other decks other than the Panasonics? Some here have said that the JVC decks are better for some jobs. You might try that.
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  3. Member DB83's Avatar
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    It is a total lottery when trying to play back EP on a machine that did not perform the original recording. I have had several decks over the years and many tapes were recorded in EP. On the deck I use now, some play fine and others are almost un-watchable and no manner of tracking adjustment will cure it.
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  4. Video Restorer lordsmurf's Avatar
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    I've written a preliminary document on this, but it's mostly just a bunch of notes.
    I'll be working on it in early 2011 and will publish it.

    Contact me in about 60 days.
    Want my help? Ask here! (not via PM!)
    FAQs: Best Blank DiscsBest TBCsBest VCRs for captureRestore VHS
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  5. Thanks Lordsmurf... I'll definitely pay for whatever you write up.

    DB83 and oldfart13 -- I tried these tapes in everything from cheap consumer units, an ancient SVHS deck, an AG-7750, and an AG-1980, and no luck. BUT.... on a whim I put a tape in my neglected Panasonic AG-7150 and I was shocked... the picture quality was almost perfect, though the HiFi track wasn't detected. I guess I can live with that. The next tape I put in played great, too. I'll probably hold off on VCR alterations until I hit tapes that nothing plays.

    I guess I'll have to chalk up the AG-7150 as a niche unit that deals well with problem SLP tapes, or at least the tapes I have.
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  6. Preservationist davideck's Avatar
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    You could try adjusting the height of the tape guides on one of your guinea pigs. You might be able to adjust the guides while the tape is playing and notice the changes in the picture immediately.

    Lots of info in Chapter 7;

    http://books.google.com/books?id=eRhJ1dni05sC&pg=PA197&lpg=PA197&dq=vcr+tape+guide+adj...adjust&f=false
    Life is better when you focus on the signals instead of the noise.
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  7. Member edDV's Avatar
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    Right, you need to become a VCR alignment geek to go beyond manual or auto tracking. Good news is most of the VCR service books are now in Google Books mostly free access.

    The issue is most of these problem tapes were recorded on a deck that was out of spec due to wear. The trick is to un-align a VCR to match the original recorder. You may need an oscilloscope to do it right.
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  8. Member PuzZLeR's Avatar
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    Oh boy, if you were unable to get it to play right on a Panny 1980, or a pro-model 7750, then, as was said, it's a lottery after that. Glad to see you found a consolation prize at least.

    I honestly don't believe there's any logic to these things. It's really what machine feels what is most comfortable for them, especially since the original recorder may not be around any longer. It may play on a "Model X", then maybe another same "Model X" different machine may play tons of tracking fuzz, simply because it has one speck of dust in its heads too much, or even too little, or the heads need a certain exact wear-and-tear or "breaking in", or the stars and planets weren't aligned correctly enough for it.

    This is total variable, as is the case for analog in general. This is my experience. I remember a GE died on me, like in 1998 or so, and its content wouldn't play as well on other machines (lots of tracking errors). I replaced it with another exact, and newer, GE model, and to my surprise, the problem continued on it as well.

    Huh?

    Since then, I gave up trying to figure out the idiosyncrasies of analog in general.

    Good luck my friend. Sorry I couldn't help you further.
    I hate VHS. I always did.
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  9. Member edDV's Avatar
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    There is logic. You need to adjust the playback heads to trace the recorded track. Logical as Spock would say.
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  10. I came across some more problematic EP (SLP) tapes this morning, which kept splashing a noise band across my video no matter how I played with the tracking control. I decided to go into the VCR unit (AG-7150) to look for a fix. I read the AG-7750 service manual and isolated one of the mechanisms associated with tracking: the entrance guide post (see attachment, in yellow box). Unfortunately this needs a notched screwdriver, but I found a piece of small, notched metal out in my workshop and was able to use that. By turning this a quarter turn to the left, the tracking improved, getting rid of the band. I verified by going the other way and lost the video signal, so I put it back the other way. It's working great so far. Hopefully this is a step in the right direction for a cheap and dirty VCR fix.

    Looks like this confirms what davideck recommended above. I wouldn't do this on my prime units like my AG-1980, of course, and I do recommend taking pictures before doing any adjustments so it's easy to put things back where they were.
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    Last edited by timmus; 9th Jan 2011 at 16:30.
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  11. Also I found some relevant info to this kind of repair here: http://books.google.com/books?id=eRhJ1dni05sC&pg=PA197&lpg=PA197&dq=post+adjust+screwd...ed=0CBMQ6AEwAA

    EDIT: The type of screwdriver / driver bit needed to turn the post head is called a "spanner bit". Took a bit of Googling to figure that out. They seem to be in most kits with security bits.
    Last edited by timmus; 9th Jan 2011 at 22:09.
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  12. Member
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    Thanks for the book link. I'm at the stage where I will now have to fix my own equipment if I want to get any vcrs repaired. The shops will no longer handle them. At least one store in my area still supplies the belts, tires, pinch rollers, etc. or can order them in. By way of return, if you are in Canada and need parts like tires, belts, etc. try here:

    www.russellind.com

    under PRB and EVG. You can also get things like needles for your turntables from here.

    Just found out about them today from my local parts store so anything I can't get I can always order in....
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  13. Member
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    Found your site tonight in my search for an answer to my problem. I have been having a heck of a time finding a service manual for an NTSC AG-7750 (PAL seems available everywhere) as mine has been sitting for nearly a year because I can not get it to track properly. If I jog shuttle I can see picture, and a great still frame, but from frame to frame I get a large band of noise. If I hit play it looks good for a second, and goes out again. I tried adjusting the guides with no success, and I do not see any motion on the Video level/tracking needle anymore. Of course all of this is with the TBC off as once it's on there is nothing on screen.

    Any insight in this would be most appreciated. I hate seeing good gear not being used and I have a LOT of tapes to move to DVD.

    Thanks
    Joe
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