Is this Panasonic AG-1970 defective?

[Brad]

I've tested three EP mode tapes so far and all show these weird pulsating lines in the chroma, including a commercial release that looks normal on two regular VHS machines. It sort of looks like every other line is inverted from what it should be. SP mode tapes look fine!





Also, shouldn't there be some sort of blue VCR screen when nothing is being played? If this one is outputting any signal at all when tapes are stopped, no device I've tried can detect it. I initially thought the machine was completely broken.

[NJRoadfan]

The AG-1970 and 1980 don't output blue screens.

[aedipuss]

ep and slp are fairly machine dependent. the narrower tape band make head alignment critical and sometimes only the machine that recorded it will play it back with good results.

it suggests the 1970's heads aren't properly aligned if others will play it ok.

[jagabo]

You are seeing hanover bars. That's native to PAL video.
http://en.wikipedia.org/wiki/Hanover_bars

You need to use a de-hanover filter. Search for "hanover" in these forums, you'll see some examples.

[Brad]

The AG-1970 is an NTSC machine and my tapes are NTSC.

[PuzZLeR]

I have a 1980, so not sure if I can help.

Maybe it's your proc amp settings (if you're using one)? For example, too much unity gain with luminance can create artifacts. Are you using the other two VCRs in the same chain?


Also, if you're using the unit's internal TBC, which is field-based IMO, turn it off. The 1980 many times outputs the wrong field order, so personally I always keep it disabled and just use an external TBC.


As well, maybe a tape cleaner can help? It's helped for my 1980's picture and sound when needed.


A few more details on your capture setup can help, including software, and capture device and settings.

[vhelp]

i am suspecting that this is a recently purchased machine and that you are tring some tapes for the first time and only now realizing this particular problem.

it could be your vcr and capture card. i assume you are going the lossless yuy2 route.

if is not your vcr, then it is your capture card. try other cards to see how they react to this vcr, remove other in-between devices and so on.

if the tapes capture better on a different vcr then its a safe bet that the units head have worn alignment issues of some sort. i once read somwhere that these units do not handle EP recorded tapes very well.

here's a test:
if you have another non-AG-1970 vcr brand, good condition vcr, put in a good blank tape (can get a radio shack or a&p) record something in EP mode, then plaback and capture it in that vcr and review the results:
if the capture proves better, then its safe to assume your capture card is not the problem, or else it is, part of the problem.
if the capture proves better, then:
put that tape into the AG-1970 and playback that while capturing it, and review the results:
if the capture proves better, then it was how the tape was recorded to on other vcrs.
if the capture proves worse, then it is that particular vcr with the problem.

let us know how you made out with this test, if you end up performing it....good luck.

[orsetto]

i once read somwhere that these units do not handle EP recorded tapes very well.

This is true only if the unit in question is a beater with worn heads and/or mechanical issues. Ordinarily, the AG1970, AG1980 and AG5710 are rather better at tracking EP/SLP than comparable JVC models with similar TBC/DNR: that is one of the reasons many of us keep both Panasonics and JVCs on hand to cope with large, varied tape collections.

I agree the AG1970 TBC is ineffectual at best and causes problems at worst: better to leave it turned off for most tapes. The only tapes it helps with are those with luma overload. Try different positions on the front panel "Noise Filter - OFF - Edit" switch: I have seen this cause lines similar to your samples.

These Panasonic AG models go off the rails entirely with certain tapes, as do the various JVC DigiPures: when this happens, sometimes the only recourse is to use the more garden-variety VCR that seems to play them with the least degradation.

[Megahurts]

Does the problem exist when recording in EP mode on the same AG1970?

Does the problem exist when VCR is connected to a TV?

[Brad]

Thanks for the replies. This VCR must be screwed. Today I tried to play two other EP tapes and just got grey noise for video. Auto tracking fail? I wasn't able to get anything with manual either. The audio meters indicated that it was playing something but I didn't check to see if that was just noise as well.

Then I tried "EP tape #3" that played on Saturday when I had used manual tracking. Nothing with both auto and manual. Then I tried EP tape #1 that I had played Saturday, and it came up right away via auto tracking (still the lines problem mind you). So I eject it and reinsert tape #3. It too suddenly played with auto tracking...

Enough to drive a guy nutty.

Maybe it's your proc amp settings (if you're using one)?
Are you using the other two VCRs in the same chain?

No proc amp (if you mean the hardware, as opposed to the capture card's settings). No other VCRs.

Also, if you're using the unit's internal TBC, which is field-based IMO, turn it off.

Tried TBC both on and off, EDIT mode on and off, sharpness low and high, etc.

As well, maybe a tape cleaner can help? It's helped for my 1980's picture and sound when needed.

What kind?

A few more details on your capture setup can help, including software, and capture device and settings.

VirtualDub 1.9.11 capturing 4:2:2 to Ut Video lossless. I have several capture devices I can try but the Diamond VC500, ATI 600 USB, and an AVerMedia PCIe card all show the issue. S-Video straight from the VCR to the capture device. I would try composite but I would need to go buy a BNC adapter, and in any case I don't want the VCR if I'm forced to use composite.

i am suspecting that this is a recently purchased machine and that you are tring some tapes for the first time and only now realizing this particular problem.

Yup just got it.

if you have another non-AG-1970 vcr brand

Unfortunately I don't have any others with me right now.

Try different positions on the front panel "Noise Filter - OFF - Edit" switch: I have seen this cause lines similar to your samples.

The picture varies with the different settings, of course, but the lines don't go away.

Does the problem exist when recording in EP mode on the same AG1970?

Hmm... I'll have to get back to you on that. Would that help to diagnose the problem? Obviously my actual purpose for this machine doesn't involve recording tapes.

Does the problem exist when VCR is connected to a TV?

I don't have a TV with me, either. My Dell monitor has an S-Video input, and the lines show up there as well.

[PuzZLeR]

Maybe it's your proc amp settings (if you're using one)?
Are you using the other two VCRs in the same chain?

No proc amp (if you mean the hardware, as opposed to the capture card's settings). No other VCRs.

Yes, I meant an external proc amp since it does cause funky artifacts with bad settings. However, I doubt the capture card's proc amp is causing your problem.

What I meant with other VCRs is if you're testing the same tapes within the exact same chain/setup, in place of the 1970 (but I see that you did).

Try different positions on the front panel "Noise Filter - OFF - Edit" switch: I have seen this cause lines similar to your samples.

The picture varies with the different settings, of course, but the lines don't go away.

If the 1970 is similar to the 1980, there should be two similar switches. One says "Auto-Wide-NOR", the other one "Detail-NOR-Edit". I'm good with NOR and Detail respectively, but I hear the 1970 may have a different agenda when it comes to DNR. At any rate, I would play around with both a bit.

As well, maybe a tape cleaner can help? It's helped for my 1980's picture and sound when needed.

What kind?

I had success with a Maxell VP-100 VHS S-VHS Dry Head Cleaner (available at B&H). It corrected my 1980 when it was outputting extra noise in the picture and made the audio sound nicer when is started sounding a bit muffled.

I'd say, from experience, any Maxell head cleaner is capable of some magic and pleasant surprises. Hopefully you have one around.

Even though it's only $5, I'm not insinuating you drop more cash to try and solve your problem. I'm sure you know the importance of one regardless. I'm suggesting that, in a case like yours or with any VCR, they can be a final dealbreaker in decisions determining if a VCR is broken/needs outside servicing/etc.

[orsetto]

If the 1970 is similar to the 1980, there should be two similar switches. One says "Auto-Wide-NOR", the other one "Detail-NOR-Edit". I'm good with NOR and Detail respectively, but I hear the 1970 may have a different agenda when it comes to DNR.

The AG1970 and AG1980 are 95% identical in operation, but differ greatly in their TBC/DNR circuits. The 1970 does not have the widescreen switch (Auto-Wide-NOR), its TBC is virtually useless for most tapes, and it has DNR in name only. So the "NOISE FILTER: On-Off-Edit" switch in the 1970 functions differently than the similar (and identically located) "Detail-NOR-Edit" switch in the 1980. The alleged "noise filter" of the 1970 apparently doesn't exist in the unit: setting the switch to "off" does absolutely nothing. Setting it to "Edit" kicks up the detail enhancement in interesting ways, which is sometimes helpful but usually overkill. Edit also defeats the picture adjustment slider.

In the 1980, the "Detail-NOR-Edit" switch actually does control a highly effective DNR circuit (but unfortunately cannot turn it completely off). The Detail setting differs little from the NOR setting in any 1980 I've used. The Edit position almost always outputs a terrible chroma-noise-riddled, oversharpened signal, so is rarely (if ever) useful. As with the 1970, the Edit setting in the 1980 also defeats the picture adjustment slider.

vaporeon800 has said these switches are not having any effect on his particular tape problem, so his issue lies elsewhere (either random tracking incompatibility with these specific tapes, or the 1970 in question has failing heads, circuits or transport).

[jagabo]

The AG-1970 is an NTSC machine and my tapes are NTSC.

Sorry, I missed the 720x480 frame size. Filters for removing hanover bars may work because the defect here looks very much like them. A video sample would be useful.



The chroma channels are out of spec too.



I don't know if that's a hint about what's going on. Maybe some of the heads have problems?

[Brad]

I'm guessing the latter issue there is just me capturing with the saturation set too high for this tape.

I did a recording of test patterns using the AG-1970. Hit record, played the DVD through, changed the mode switch from SP to EP while recording, played the DVD through again, hit stop. Then I captured the tape playing on the same machine and chopped it up for the Ut Video clips I've attached:
- SP
- SP/EP showing the switch
- EP with the capture device's saturation set ridiculously low (the lines are barely visible in direct playback, and obvious if you bump it back up with a software filter)

Another worry: why is there rainbowing on both SP and EP?! The input and output are both S-Video, and viewing the DVD playback passed through the VCR without recording displays no such issue.

I sent the seller a link to the thread and he refunded without me asking, and even refused my subsequent offer of paying what it cost him to ship it. So that's a nice happy ending, at least. Now I need to find someone who will take this junker and track down another one.

[jagabo]

Don't those decks have separate heads for SP and EP? It looks like one of the EP heads is having problems.

[lordsmurf]

With Panasonic VCRs, more than likely it's bad caps these days.
That may be all it is.

I would not junk it. (Send it to me. Always fun to tinker with VCRs.)

Next time, get the AG-1980P units instead. It has better quality, when in good shape.

[Brad]

Don't those decks have separate heads for SP and EP? It looks like one of the EP heads is having problems.

My understanding is that all VCRs accomplish EP mode using a second pair of heads, so yeah, seems so.

Send it to me. Always fun to tinker with VCRs.

How about tinkering with that VCR comparison thread instead?

[Brad]

I picked up a BNC to RCA adapter today. The composite output doesn't display the issue. So, I see two possibilities:

1. The signal coming off of the heads is clean, and the S-Video electronic section is screwy.
2. The signal coming off of the heads is messy, and the composite output happens to remove the effect by filtering.

AG-1970 -> Diamond VC500, YC vs CVBS


AG-1970 -> ATI 750 USB, YC vs CVBS


Meanwhile, I got a DPS-470AV and captured some video by YC -> SDI. I guess it must filter the chroma the way that jagabo did.



I'm currently trying to figure out if there is any way to change which lines are captured so it doesn't grab so much of the vertical blanking interval and crop the bottom of the image, but on the plus side I happened to see some neat VITS on this tape.

[orsetto]

I picked up a BNC to RCA adapter today. The composite output doesn't display the issue. So, I see two possibilities:

1. The signal coming off of the heads is clean, and the S-Video electronic section is screwy.
2. The signal coming off of the heads is messy, and the composite output happens to remove the effect by filtering.

1. Probable: it is not unusual to find a used AG1970, AG1980 and AG5710 with defective connector issues. Most commonly the front panel inputs are broken, but I've also had units where just the audio output in one of the jack sets is dead, or the s-video is dead but the composite works. These are all old VCRs now, most were beat on by pros with no restraint, and unlike Panasonic consumer VCRs where the entire VCR is based on one tiny consolidated bulletproof motherboard, the AG series is chock full of separate boards and connectors that multiply failure points (cold solder deterioration, internal wiring damage, socket pin damage). Since you have nothing to lose, you could try pulling it apart to see if the inside of the rear connection panel has any obvious problems with loose cables or broken corroded solder. The s-video sockets themselves are prone to symptomatic, hidden internal damage that can be fixed by replacing the socket (but that isn't always easy).

2. Possible, but I'd place my bet on physical connector/wiring issues first, physical head wear second, and circuit board issues a distant third. Unlike the AG1980, the AG1970 circuits are tidy and not nearly as prone to aging issues.

Next time, get the AG-1980P units instead. [...] It has better quality, when in good shape.

...Oh wait, you aren't joking?

The AG1970 beats the AG1980 to a bloody pulp if you pit them in a build quality/durability contest. Actually, there is no contest: the AG1980 is absolute crap from stem to stern. When brand new, or if you do a painstaking expensive restoration today, it can provide fantastic output quality (if one needs and can appreciate its particular noise smoothing and TBC characteristics vs very similar JVC). But mechanical and electrical reliability is utterly atrocious compared to the previous AG1970. The biggest VCR design mistake by Panasonic was not packaging the superb AG1980 TBC/DNR as a rugged module ala JVC. The second-biggest mistake was not leaving well-enough alone with the AG1970 transport and electronics. Instead of being a VCR for the ages, the AG1980 became a flaky undependable money pit. Nice if you can afford the maintenance and find a good repairman: much like an exotic sportscar or vintage Hasselblad/Rolleiflex camera.

[PuzZLeR]

Thank goodness I've pretty much finished my tape transfer project a while ago and don't have to care so much about the future of my 1980. I keep it around for the odd new tape that comes in, from a friend, or the rare redo, etc, and I do have the JVC as well.

Yes, the 1980 was quite the flake over the course of my projects. It had "moods". If I were doing it all over again this time I'd pick up a 1970, even upon reading about this one's issues.

[Brad]

Passthrough from front composite input to S-Video output. Crazy checkboarding and flickering in colors. The yellow patch has a greenish column running through it.



I've got another one coming, purchased for less than the previous. Hopefully it performs as expected...

[NJRoadfan]

The checker boarding looks like cable crosstalk. Does it still happen if you input the same signal via S-Video?

[Brad]

Can't try it with that device, but here is a comparison with a DVD. Same known-good output cable used, going to the same ATI 600 USB.

Composite in (front)


S-Video in (back)

[jagabo]

The checker boarding looks like cable crosstalk.

No, it's from poor (no?) separation of the chroma from the luma channel. Ie, a poor (or no) comb filter.

[Brad]

And here's an SP recording of the pattern a few posts up. There's an oscillating wavy pattern over any fields of color. What confuses me is the added rainbowing not present in the passthrough image. Is it caused by heterodyning the chroma? (Any idea what frequency that is where it appears?)

[lordsmurf]

How about tinkering with that VCR comparison thread instead?

Yes, I can do it now.

Earlier this year ... not so good for me. Lots of false starts.

[Brad]

I think you hit the nail on the head with "no comb filter", jagabo. I recaptured the pattern above with the ATI 750 USB, for its higher chroma resolution over S-Video.



Greyscale(). Cross-luma everywhere but near-perfect diagonal resolution.


For comparison, Greyscale() of the ATI 750 USB's own comb filter. Cross-luma is eliminated (in stills) but the diagonal resolution is nuked in areas of cross-color.


Merge(last,last.Trim(1,0)) of the AG-1970 passthrough.


Of course, as with real 3D comb filters, merging with the previous frame totally screws things whenever anything moves. And there's still a damned bar partway through the image where the colors are all wrong.

[jagabo]

I ran a test with a composite source wired directly to the luma pin of an s-video port. There was no color at all because nothing was connected to the chroma pin, but the captured greyscale video had exactly the same checkerboard pattern anywhere there should have been color.

[Brad]

What happens if you split it and wire to both luma and chroma? Explosion?

[jagabo]

What happens if you split it and wire to both luma and chroma? Explosion?

You get color.

I scrounged up a very old, crappy, DVD player with both composite and s-video outputs, and cobbled together some wiring. I used an ATI TV Wonder HD 650 USB to capture. I didn't calibrate anything so don't expect perfect levels, colors, or a great picture -- that's not the point of these examples. But here's what I get with the composite output of the player connected only to the luma pin of the capture device's s-video input:



With the composite output of the player connected to both the luma and chroma pins of the capture device's s-video input:



Finally, with an s-video cable from the player to the capture devices s-video input: