Hi,

This is my first writing to forum. Have been reading forum & studying VHS-capture related topics fwe months. (English is not my first language so sorry about possible typos/errors etc. :))

Problem/question: DVK artefacts.

PAL-land, equipment’s:
* VCR: JVC HR-DVS2
* DVK-100: Model G. Out: Output. Tested that front panel adjustments affects to CAM1 and CAM2 inputs.
* ES10: AV1/Scart S-video out. To S-Video in I have fabricated one s-video cable with luma resistance (I found link how to make cable from this forum)
* Capturing Card: One I ordered has not arrived yet. Currently testing / verifying ES10, DVK and connectivity with cheap USB capturing dongle using old commercial VHS tape.
* WIN7 to capture with Virtualdub 1.9.

DVK-100 has been set as following:
* Dip switches according to manual.
* Chroma Key-part -> all reset.
* Color Proc -part reset (pushing the adjustment knob) to all selectors.

Observations: Adding DVK to workflow causes artefacts.
There are four continuous frames in attached picture. Upper row has frames without DVK and lower with DVK.

Lower(DVK) row has artefacts / reflections / visible from next frame (example head of the man standing behind). This can't be expected behavior?
Camera is moving in this scene.

It would be great if someone could explain what may be the cause of these artefacts?
Is there something that can/should be done? Am I doing something wrong?
As for now I have app. 20 VHSC tapes to capture after I have received capture card and I will of course add devices to the chain only as needed, but I am now little bit worried about observed artefacts when adding DVK.
Added also ES10 between VCR and DVK but it did not make any difference to these artefacts.

Thanks in advance

-- merged --

Well, need to change some capacitors. Four of them has bleed their internals to the board :). (Attachment)
Maybe the wisest would be to change all caps.

That's almost certainly factory-placed glue, electrolyte leakage is much thinner and will appear like a coating of oil or thin white/crusty film and won't be raised off the surface/hard like that. Could still be capacitors though. Unfortunately, usually you can't tell by looking at a cap if it is bad unless there is obvious bulging or leaking, but a normal looking capacitor can still be bad. If I was you and had these issues, I'd probably do a full recap since there aren't that many capacitors in these to begin with and that's a relatively easy first step.

I've heard the fans can also introduce picture noise, so you might want to try unplugging that first and see if you get the same issue. If so, you could either replace the fan, or power the fan separately from a different external/separate power supply.

LS may know more since he uses/sells/services them from time to time I believe.

There are certain items where I advise people to either buy it from me, or not buy it at all. The DVK is such an item. It needs multiple areas of attention, including setup, locating the signal pathways (varies by version), lockdown, and fan removal (which often requires board de-solder mods).

It's not an item for newbies --- at least not until I'm done with it.

What is shown here is DataVideo glue.

I've never understood why they do this, so I asked Gemini: "Why do some manufacturers add glue to soldered capacitors on mainboards." And the answer was:
- To prevent the capacitors from vibrating and causing noise or damage. -- MAYBE? Interesting.
- To improve the reliability of the solder joints. -- MAYBE.
- To protect the capacitors from physical damage. -- NO.
- To improve the appearance of the mainboard. -- NO.

So that just added questions, not really answered anything here. I've always suspected it was to keep solder secure (the 2nd response from Gemini), but I've always dismissed that, because the boards are in a hard case. You could probably throw this case against a brick wall, and it'd hurt the bricks more than the metal case.

The forum downres'd that long image, so hard to see now. But I don't see anything wrong here. What I see is temporal offset of half a frame, compounded by a deinterlaced mess. That could be caused from bad DVK settings. Or from bad post-DVK interlace processing -- meaning somewhere in the capture card, or more likely the capture software (specifically the capture settings). I need to see full sized previews, not a small "film strip" image.

But remember DVK is not a TBC, but more like a TBC(ish). Weaker TBCs, and TBC(ish) device are generally not full transparent to the source. ES10/15 is certainly one of the least transparent devices, adding multiple issues to video (AGC, posterization, luma gain, etc). If set wrong, the DVK can amplify noise off the ES10/15.

With DVS2 in use, there is zero reason for ES10/15 here, aside from tearing issues (nth gen). So run DVS2>DVK.

"cheap USB capturing dongle" is obvious here. Don't use quality VCR, TBCs, then connect a POS to it. That's like spending $3k on an SLR camera, then attaching a $50 Chinese plastic lens to the front. Don't do that.

Adding a quality capture card, removing ES10/15 from workflow, and verifying all DVK settings (not easy for newbie), should yield better results.

It indeed was glue, and it made really hard to get those caps out. I ended to use small snap-off knife to carefully make a cut to glue. I replaced all mainboard caps and measured old caps values:
13 x 16V 470 µF -> one was 392 µF and others in range 436 -477 µF
1 x 35V 2200 µF -> 2267 µF
2 x 35V 470 µF -> 436 -440 µF
2 x 16V 1000 µF -> 922-935 µF
All old caps are well in tolerance values. Tested and the replacement had no effect to artefacts :-( but that was expected outcome as I had first measured old caps.

Fan was unplugged.

Here is link to original image (2886x1154 pixels). Would this be ok?
https://drive.google.com/file/d/1rE5...ew?usp=sharing
Capture settings was identical to both examples in attached image.
Yes, this was also my plan (unless I face such tape / capture that there is a need to try if ES10 would help with the picture). All tapes are camcorder/VHSC with only few viewings.
I'm still waiting my capture card and currently testing equipment’s with low-cost USB-dongle. Maybe I should wait until I have better card and continue tests after that...

Thanks to both about the comments and suggestions. Great forum :-)

Since capacitors have been ruled out now, It almost looks like some sort of frame rate conversion is happening here, like you're working with PAL content, but capturing at an NTSC frame rate where it tries to make "half" frames and you might end up getting an output like that. If your capture card isn't set to capture frames at the native rate, I'd try that first, but given everything else you've tried, I assume you've looked at the output file frame/field rate matches your source to verify.

Thanks for pointing the directions I should investigate.
I will re-check capturing settings and take notes of all the steps I make.
As a newbie it is indeed possible that I have just made a simple error at some point (actually hoping this being the case:))

Between replacing the junk card, and the software/settings, I think that's the case here.

Well, this was interesting.

DKV-100 manual:
Dip Switch 2: OFF = 0 IRE, ON = 7.5IRE input/output

Since in PAL land I had it OFF but among other tests I tested this dip switch also with “ON/7.5IRE input/output” and the "ghosting" artifacts had gone away! :relief:

When I first set DVK up I had just googled:
https://en.wikipedia.org/wiki/IRE_(unit)
M-NTSC: Reference black 7.5 IRE
B/G-PAL: Reference black 0 IRE
And came to conclusion that PAL it should be OFF…

Waiting for the better capture card to continue experimenting with my setup & Virtualdub :-)

(Other positive outcome of all this: at least DVK has now new caps)

I am starting to agree with the last sentence...

-- merged --

FYI, it was indeed the capture card. In the last few weeks I have been studying and testing the capture and I am satisfied with the quality. (I'm on a shoestring budget for digitization, so I got a used Osprey 260e card. On the other hand, I'd be a little interested in getting one of the Pinnacle devices for sale on the site and compare it to the Osprey...)