VHS tape issues: chipmunk audio with static?

[Disharmony]

I received over a hundred tapes from someone whose late mom recorded in the 90s. Almost the entire batch are playable and then there's probably 30 or so tapes that have this issue.

I don't think I've seen anything like it before. When playing it on an AG-1980P, some show a partial picture then becomes distorted after a second while the others start out completely distorted. I tried it on a basic JVC SVHS player hooked up to a DMR-ES18 and it's just a blue screen with chipmunk voices.

It's not a dirty head because any other tape plays completely fine whenever I switch back and forth. I suspect PAL but we're not a PAL country and shouldn't it be just black and white if that was the case?

[lordsmurf]

The chipmunk'd audio suggests mode (switch?) issues on the recording deck/camera. But the video noise + audio problem suggests re-recordings with original recording bleed-through. Maybe even both.

It may be compounded with misalignment, but that's not the main issue.

When you run into bad tapes, you almost never have just one issue. The errors tend to be multiples, and multiplied or compounded.

Odds of signal recovery 1%

[themaster1]

Best guess (knowing other tapes "play fine" according to O.T.S)
Sticky tape . it sticks to the drum, lower the RPM (good RPM is critical)
Solution: clean the tape ( tape rewinder/cleaner / vhsislife machine)

[lordsmurf]

Quote:

Originally Posted by themaster1

Best guess (knowing other tapes "play fine" according to O.T.S)
Sticky tape . it sticks to the drum, lower the RPM (good RPM is critical)
Solution: clean the tape ( tape rewinder/cleaner / vhsislife machine)

I would not make that leap yet.
With your hypothesis, Step 1 = look at the tape. Is it dirty in age way, or flaky in any way?

[timtape]

Does the AG-1980P play SLP/EP recorded tapes?

1. plays at about 3 times recorded speed suggesting an SLP/EP recording.

2. at about 2 times recorded speed suggesting an LP recording

4. at abt 3 times suggesting recorded at SLP/EP speed.

All assuming SP playback speed.


Poor quality audio even for SLP/EP linear speed.

[Disharmony]

Quote:

Originally Posted by themaster1

Best guess (knowing other tapes "play fine" according to O.T.S)
Sticky tape . it sticks to the drum, lower the RPM (good RPM is critical)
Solution: clean the tape ( tape rewinder/cleaner / vhsislife machine)

Quote:

Originally Posted by lordsmurf

I would not make that leap yet.
With your hypothesis, Step 1 = look at the tape. Is it dirty in age way, or flaky in any way?

Tape is clean. No visible molds, no flakes. But to be sure, I also ran all tapes through the VHS is Life cleaner twice. Same result.

Quote:

Originally Posted by timtape

Does the AG-1980P play SLP/EP recorded tapes?

Yeah, roughly 60% of the tapes I've played on it in the past were SLP. This is the first issue I've encountered wherein I'm completely baffled and out of ideas other than possibly trying it on a PAL player I have tomorrow just to see what happens.

[timtape]

The fact that it plays what seems like an NTSC SLP/EP speed tape at NTSC SP speed, ie: 3 times speed suggests it's an NTSC recorded tape. If it was PAL recorded and was played at NTSC SP there should be a 3.6 times speed differential, not 3 times. SLP/EP was designed to run at 1/3rd SP linear speed.

As a tech I'd try and manually optimize playback at the A/C head. The control track read may be as poor as the audio is poor, and sharing a common cause. The slower the recorded speed - and SLP/EP is as slow as VHS gets - the more vulnerable to a control track signal so weak that the VCR cannot even lock onto the correct recorded speed, which may be going on here.

[Disharmony]

For what it's worth, the guy said that he needed a super old VCR to be able to play them and check he's not giving something to me that he's not supposed to.

I never got the chance to have him expound on that but is there anything on the earlier VCRs that could explain why this is the byproduct?

Quote:

Originally Posted by timtape

The fact that it plays what seems like an NTSC SLP/EP speed tape at NTSC SP speed, ie: 3 times speed suggests it's an NTSC recorded tape. If it was PAL recorded and was played at NTSC SP there should be a 3.6 times speed differential, not 3 times. SLP/EP was designed to run at 1/3rd SP linear speed.

The slowed down clip you played is super interesting. Because now that I could tell it's from the Hallmark Channel, I can confirm that the content is something from the same other tapes I was able to play back normally. So, why is this tape different from that batch?

[timtape]

Quote:

Originally Posted by Disharmony

So, why is this tape different from that batch?

That's the question. But without having the tape to test it's impossible to say for sure. You probably need to send the tape to an expert.

[Mixed Media Disc]

If the content is extremely important, try an old Panasonic VCR that allows you to manually select SP/LP/SLP during playback like a record player. A lot of people think the machines I speak of are broken because they test it with Little Mermaid or Toy Story and just say "drowsy" in description. Turns out they don't know the speed needs to be manually changed on a tape-by-tape basis.

[timtape]

Quote:

Originally Posted by Mixed Media Disc

If the content is extremely important, try an old Panasonic VCR that allows you to manually select SP/LP/SLP during playback like a record player. A lot of people think the machines I speak of are broken because they test it with Little Mermaid or Toy Story and just say "drowsy" in description. Turns out they don't know the speed needs to be manually changed on a tape-by-tape basis.

The later model VHS decks didnt require manual changing of tape speeds. They automatically sensed the speed information in the tape's control track. I can see that using one of these old machines and manually switching to the correct sounding speed might get you roughly in the ballpark, but the control track is the only way the picture information can be accurately tracked. The video timing tolerances are far tighter than for capturing just the linear audio track. My guess is playback speed had to be manually selected back then because of technical/cost limitations at that time. Also if manual speed selection still had a use sometimes, did they carry that manual override feature over to any of the later better featured models?

I hope you're right but have my doubts here.

[Disharmony]

Quote:

Originally Posted by Mixed Media Disc

If the content is extremely important, try an old Panasonic VCR that allows you to manually select SP/LP/SLP during playback like a record player. A lot of people think the machines I speak of are broken because they test it with Little Mermaid or Toy Story and just say "drowsy" in description. Turns out they don't know the speed needs to be manually changed on a tape-by-tape basis.

Can you name some VCRs with manual playback selection? Can't really trust Google now with AI mucking up the search results.

[Mixed Media Disc]

Panasonic PV-1750 has manual playback speed selector. And to answer other question, no, you cannot manually set the playback speed on newer VCRs that have automatic detection of the speed.

[Haunted_TBC]

I have a Samsung mono VCP (yes, VCP, as it lacks the record function) from the mid 1980s and it is SP only. The uploaded clips (at least in the audio sense) sound exactly like LP and EP/SLP tapes when I put them into the deck, so they definitely need to be played at the correct speed first before analyzing problems more closely.

[timtape]

Quote:

Originally Posted by Haunted_TBC

I have a Samsung mono VCP (yes, VCP, as it lacks the record function) from the mid 1980s and it is SP only. The uploaded clips (at least in the audio sense) sound exactly like LP and EP/SLP tapes when I put them into the deck, so they definitely need to be played at the correct speed first before analyzing problems more closely.

Yes but the particular twist here is that reportedly other EP tapes from the same owner play well on the OP's AG 1980. Those tapes dont need playing on another machine for correct playback speed so why dont these?

[Haunted_TBC]

I would say due to the speed control track info being distorted/too weak. They need to be forced to play at the correct speed, because the VCR is clearly mistracking/not realizing the true recorded speed of the tapes.

[latreche34]

This is a speed compatibility problem, your tapes are recorded in a speed (who knows what?) that is not compatible with your VCR or the VCR is enable to lock onto for an unknown reason, AG-1980P is a PAL machine (or P stands for Professional?) and you stated you are not in a PAL country, this should give a clue. This is as far as my guess goes since I don't have access to the tapes.

[timtape]

Quote:

Originally Posted by latreche34

This is a speed compatibility problem, your tapes are recorded in a speed (who knows what?) that is not compatible with your VCR or the VCR is enable to lock onto for an unknown reason, AG-1980P is a PAL machine (or P stands for Professional?) and you stated you are not in a PAL country, this should give a clue. This is as far as my guess goes since I don't have access to the tapes.

It appears the AG 1980P is NTSC. The front cover of the Owner's Manual has the words" Professional/Industrial Video" so yes the P may stand for Professional.

Interestingly the specs state that it does SP (33.3mm/s) and SLP/EP (11.1mm/s). No mention of LP which I assume is 22.2mm/s.

Like you I cant be sure what's going on here without testing a sample tape for myself.

[Disharmony]

Quote:

Originally Posted by Mixed Media Disc

Panasonic PV-1750 has manual playback speed selector.

Thanks! I also noticed that our very first VCR (an Omnivision too) had a manual playback speed selector upfront too. Unfortunately, eBay is littered with "for parts only" units.

Quote:

Originally Posted by timtape

Yes but the particular twist here is that reportedly other EP tapes from the same owner play well on the OP's AG 1980. Those tapes dont need playing on another machine for correct playback speed so why dont these?

This is exactly it. He also sent me like 200 SLP tapes from a year ago (most of which are from the same period and channel as the one the slowed down wav file came) and they all worked.

Quote:

Originally Posted by latreche34

This is a speed compatibility problem, your tapes are recorded in a speed (who knows what?) that is not compatible with your VCR or the VCR is enable to lock onto for an unknown reason, AG-1980P is a PAL machine (or P stands for Professional?) and you stated you are not in a PAL country, this should give a clue. This is as far as my guess goes since I don't have access to the tapes.

The "P" is supposedly for significantly improved picture quality. I wouldn't know since I haven't tried the plain AG-1980P. But it's definitely not PAL, NV-FS200 is the PAL counterpart of the 1980.