Advice on unstable s-vhs tapes

[Steen4]

I am in the middle of converting my old vhs tapes to cvd/vcd, but am hitting a roadblock: the original machine that I used to record a number of these tapes (an old panasonic s-vhs model, I can't remember the model number, but I bought it in about 1991) is long gone and no other vcr will play these tapes entirely properly. A technician told me that the original vcr probably was slowly losing its alignment as it aged. When tapes that were recorded on it are played back, there is a nearly-impossible-to-get-rid-of noise bar, usually in the lower part of the frame and sometimes accompanied by a buzz in the audio. I have run tapes through my JVC hr-s9911u, my Panasonic ag-1960, and my videodata tbc-1000 trying to get tapes to play back stable and noise-free, but there are still some tapes that won't play nice. I have been checking the forums for advice about vcr's that will play troublesome tapes, but none seem to be s-vhs units. Does anyone have a little insight on this? Also, would it be worthwhile to see if I can get a technician to actually 're-align' one of my decks to play back the rogue tapes, or can that be done?

[johns0]

You can realign the tape guides which bring the tape around the head and this can possibly get rid of the bar but it might throw of the alignment with other slow speed tapes.

[LSchafroth]

You can realign the tape guides which bring the tape around the head and this can possibly get rid of the bar but it might throw of the alignment with other slow speed tapes.

he's correct. I had a BetaMax doig the exact same thing. I adjusted the guides only and the line was removed and no more noise. I adjusted three different guides one at a time until they all lined up without rolling the edge of the tape.

LS

[OmegaSupreme]

Have you tried the "video stabilizer" feature on the JVC hr-s9911u?

[lordsmurf]

Some units are not "out of alignment" but merely using different tracking ranges. Magnavox is well known for this. They come "out of alignment". You've got to alter the alignment to the other "spec" (quoted, as I'm not sure it's really a spec, probably more of a machine defect).

This really sucks, I deal with it quite often. I have different machines with different alignments because of this simple little fact.

[mazinz]

also the reason why i still hang onto my older 8mm camcorder. Had the same issue as you, and when coverting those tapes over to dvd, I had to literally sit there with a screwdriver and align it as the tape played (well in some cases, not all) because the video camera used was really screwed up and lost aligment over the years.

So i use my older 8mm cam for these as i can just adjust the "heads (tape reel? not sure of correct term) so the troubled tapes do play fine. I would never do this with my main video camera obviously.

[Flying_Monkey]

A Time Base Corrector may help.

Here is an example of one:

http://www.videoguys.com/datavid.htm#tbc1000

[Roundabout]

Also, would it be worthwhile to see if I can get a technician to actually 're-align' one of my decks to play back the rogue tapes, or can that be done?

Yes, it could be done. However, by adjusting the tracking to the "incorrectly recorded" tape, all other tapes would not play correctly.

This is more of a problem with tapes recorded in EP mode than SP. I have two different brands of VCR's that the tapes are not interchangeable if they were recorded in EP. If they are SP, no problem.

There's less margin for error in EP and alignment is very critical.

If your tapes were recorded with a different azimuth each time, you'll go crazy trying to play all of them. If you have a cheapo deck you don't care about, you could just play with the tape guide adjustments while the tape is playing, being careful not to turn it too far - until the tape clears up. Then turn it back, and do the same thing with the next tape. I can't think of any other way you could do this, from a practical standpoint.

A Time Base Corrector may help.

Here is an example of one:

http://www.videoguys.com/datavid.htm#tbc1000

Ummm, I think he already has one and has tried it:

I have run tapes through my JVC hr-s9911u, my Panasonic ag-1960, and my videodata tbc-1000 trying to get tapes to play back stable

[Steen4]

Thanks for the replies, guys. I'm not relishing the prospect, since it's going to require a lot of observation and writing down adjustment amounts, but I have decided to finagle with the guides to get this job done. A lot of these tapes look to have very similar tracking (or, more appropriately, mis-tracking) characteristics, so I don't think I'll need to make a lot of adjustments between tapes. My only issue will be getting the machine back to its original tracking range after I'm done, so I'm going to adjust each guide post by quarter-turns either clockwise or counter-clockwise, make notations of the adjustments on a sheet of paper, evaluate any improvement or deterioration in quality, adjust again, and so on until the problem clears up. After I finish capturing my tapes, I'll use the notes to restore the position of each post (so glad I read about Theseus as a kid!).

OmegaSupreme: it's not a matter of 'jitters,' which would require the use of the stabilizer. The tapes have noise bars, areas where the video info is 'scrambled' due to incorrect tracking matchup between tape and machine. No video stabilizer can restore this to the video stream.

Flying_Monkey: Yes, I have two tbc's. One is in the hr-s9911u and the other is a standalone, the datavideo tbc-1000. A tbc can help stabilize the picture, but since the problem deals with tracking, there is information missing from the picture before it gets to either tbc, thus my quest for another method.

I had a vacation from work coming up at the end of October (wait 'til those little bastards try to t.p. MY damned house!), but my doctor says I have a break in one of the bones in my elbow, so I may get my vacation time a little earlier than I thought. Hell, I may be able to get two 'vacations.' Once my employer finds out I won't be able to enjoy myself with my time off, we-e-e-e-ell...

By the way, I recently posted what I feel are sorta odd results of a test I did to determine the effects of stacking tbc's for video captures. I believe you can find the post in a thread concerning (what else) "tbc stacking," but I don't know whether anyone would even find this of interest. If so, I'll try to repost it in its own thread. If anyone would care to look at it now, a forum search for 'tbc stacking' (I guess you could also search posts for my monicker) should turn it up. Thanks again to all who were gracious enough to help out.

[Megahurts]

Steen4

If your worried about restoring tape path alignment after you mis-aligned the tape guides, record a tape in EP mode before you change anything. You can always align it back to that recorded tape.

Regards,

Chas

[Alan69]

There are actually 2 possibilities, the tape alignment and tracking.

Alignment sets the overall alignment of the tape to everything, audio and video. Pretty well discussed.

For tracking, there are two components that work together. Motion of the tape and motion of the video head interact to make the total track the video head makes for each line. If you speed up the tape or slow it down, you change the total diagonal line of the head path on the tape. If you slow down the head rotating speed a bit, then doesn't make it all the way across the center part of the tape for video before it's done writing, and it follows a diagonal more 'flat' than average across the tape. If you speed it up, then it makes a steeper diagonal across the tape.

The tracking knob on a VCR adjusts the speed of one of these motors, to make the total diagonal track of the head vs the speed of the tape match what's on the tape. Don't even recall off hand which motor it adjusts tape speed or the head speed, but not needed to get the idea anyway.

So you could have an actual alignment error. For that aligning is the better fix.

Or you could have a tracking problem. Through wear or bad tracking, your old equipment had a track across the tape that's out of the range of your new equipment's ability to adjust to. Could even be your old equipment was misadjusted or assumed a different normal, and your new equipment assumes very near idea and has a too narrow adjustment range.

At any rate, it would be fairly easy for an electronics person to change your equpment. Most of these use a speed controller for the motor, they normally use a resistance to control the speed, which is the pot named tracking. Actually there's usually a resistor to set the minimum, and a pot that can go from zero to it's max range. So total resistance goes from the minimum resistor value to that resistor's value plus the pot's max. Get a pot with twice the range, lower the minimum resistor by the amount needed to put the center of the pot range back at center, and you can make a super tracking VCR with twice the tracking adjustment of normal. Costs about $5 plus a bit of time to do it, only the pot and the resistor to change.

Much easier to turn a pot than adjust the total tape alignment, quite worth modding a cheap unit to see if that's all you really need. The actual mechanical alignment is supposed to be set by the standard so it should just be differences in the motor speeds between the units, or a worn motor etc. Of course some manufacturers do have loads of dumbass in them, so it could be a real alignment error instead. Sometimes comes in handy to have a wide tracking unit if the stock units tracking is a bit narrow anyway, so it's still a good and easy first mod to see. Well easy electronics, I guess some people would probably consider the screw adjusting of the alignment easier as a first shot..

Alan