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-   -   What is a TBC? Time Base Correction for Videotapes (https://www.digitalfaq.com/forum/video-restore/2251-tbc-time-base.html)

hodgey 02-25-2018 11:20 AM

2 Attachment(s)
Quote:

Originally Posted by lordsmurf (Post 17020)
According to TVOne support, the CTB-100 and 1T-TBC share the same main circuit board -- but apparently the 1T-TBC has something added, which results in the decreased image quality. There's also a variant model which adds genlock: the 1T-TBC-GL. The only potential benefit of the 1T-TBC is that no current chipset defects have been reported by users online -- it's contained mostly to 2011 issue AVT-8710 and CTB-100 models.

I have taken some images (attached) of a newer TVOne 1-TBC (bought in 2016 or 2017 I think), and it looks as if the circuit board design has departed a bit more from the CTB-100. Taken with a cellphone camera, with sub-optimal lighting and settings, so the quality isn't great.

This unit also have issues with locked fields (similar to what's demonstrated here here) (though it's a bit visually different, as the AVT the field, while on the TVOne (not sure how to best describe it) rolls instead of being frozen still (I might be able to provide video if there is any interest). I haven't noticed any deteriorated image quality from it as reported in the linked thread, though I haven't done checks with test images, so it's possible that the image defects are present in this one as well.

lordsmurf 02-25-2018 11:56 AM

Correct. The 1T-TBC eventually also had the same problems as the AVT-8710/CTB-100. I've updated the post you've quoted with more updated/current accurate info.

The entire Cypress/AVT TBC ordeal ended quite sadly. No fix ever existed, simply a discontinued product. :(

Since Cypress/AVT serial numbers reflect the date of manufacturer, so only get TBCs made before 2010 to be safe. The AVT-8710 is green, the rarer CTB-100 is Smurfy-blue on gray (not muted blue on silver). Unfortunately, the 1T-TBCs never changed it's look, so it's not as simply as color. Must find/read the serial.

BarryTheCrab 02-25-2018 12:28 PM

This might be nutty, but with all the gadgetry and 3D printers and electronic stuff, can someone with the correct knowledge actually build a TBC? Same for VCR parts, 3D printers? It's brave new world wizardry that might be applied to old world crappery?

hodgey 02-25-2018 01:41 PM

I came across this the other day. It looks abandoned, but it suggests it's doable.

lordsmurf 03-13-2018 12:30 PM

Quote:

Originally Posted by BarryTheCrab (Post 53056)
This might be nutty, but with all the gadgetry and 3D printers and electronic stuff, can someone with the correct knowledge actually build a TBC? Same for VCR parts, 3D printers? It's brave new world wizardry that might be applied to old world crappery?

Electronics can't easily be built with 3D printers, especially not capacitors. Maybe the raw component boards can be printed, maybe a case (a flimsy one), but that's it.

Quote:

Originally Posted by hodgey (Post 53057)
I came across this the other day. It looks abandoned, but it suggests it's doable.

Interesting. :hmm:

Quote:

Originally Posted by endo
...

Your topic was moved here: http://www.digitalfaq.com/forum/vcr-...bc-memory.html

hodgey 03-13-2018 12:59 PM

Quote:

Originally Posted by lordsmurf (Post 53273)
Interesting. :hmm:


I came across another DIY TBC project here. This person is using the same A/D converter as the one in the AVT8710, with a slightly differend D/A chip and a different microcontroller. Interestingly he's using the 16-bit colour mode of the SAA7114H, while the AVT uses the 8-bit colour mode (from what I can tell at least).
So it seems like it would indeed be possible to create something using off-the-shelf parts.

BarryTheCrab 03-13-2018 02:50 PM

Regarding 3D printers
 
Quote:

Originally Posted by lordsmurf (Post 53273)
Electronics can't easily be built with 3D printers, especially not capacitors. Maybe the raw component boards can be printed, maybe a case (a flimsy one), but that's it.

My thoughts were 3D printing of rare or broken VCR parts, plastic armatures or gears, etc. Stock plastic or metal cases might be available for pennies with a little poking around. And am I wrong in thinking electronics of all sorts are available off-the-shelf for some clever under-grad to cobble together a TBC during lunch?

lordsmurf 03-13-2018 02:54 PM

I'd buy lunch. :D

Xithi 11-02-2018 08:23 AM

Connecting VCR to projector
 
Hi there,

Sorry to resurrect this old thread.
I'm a complete amateur and not interested in digitising VHS tapes, just projecting them through a digital projector.

Unfortunately some of my tapes are in bad condition, and the projector plays the video for a bit but intermittently shows 'no signal'.

Do you think a TBC could help me with this set-up?

Thanks

Max

lordsmurf 11-02-2018 08:32 AM

Quote:

Originally Posted by Xithi (Post 57098)
Unfortunately some of my tapes are in bad condition, and the projector plays the video for a bit but intermittently shows 'no signal'.
Do you think a TBC could help me with this set-up?

For mere viewing, I'd look at using a Panasonic ES10/15 recorder on passthrough.
Try that first.

Mazen_Khaddaj 07-17-2019 10:04 AM

Is TBC worth the money?
 
I want to convert old VHS tapes to digital format .mp4, it can cost me 7$ with these cheap hardware (easycap usb 2.0), or 300$+ with TBC. is it worth the money?

lordsmurf 07-17-2019 10:15 AM

Quote:

Originally Posted by Mazen_Khaddaj (Post 62572)
I want to convert old VHS tapes to digital format .mp4, it can cost me 7$ with these cheap hardware (easycap usb 2.0), or 300$+ with TBC. is it worth the money?

Easycap is a bad device, lots of quality issues. There are better cards, including USB for Win7/8/10.

Acquiring quality hardware for quality transfer is almost always worthwhile. Why forever convert VHS to look terrible? If that's the case, why bother converting at all? A VHS tape can, and should, look better than the tape. Not worse. VHS has a lot of problems, most of which can be corrected with the right equipment. Or made worse with the wrong equipment.

dpalomaki 07-17-2019 02:50 PM

Quote:

Originally Posted by Mazen_Khaddaj (Post 62572)
I want to convert old VHS tapes to digital format .mp4, it can cost me 7$ with these cheap hardware (easycap usb 2.0), or 300$+ with TBC. is it worth the money?

Nearly all, if not al,l of the people who participate believe that it is worth the money - at least to them it is worth it.

But it all depends on how good is good enough for you (and also how bad your tapes and other gear are). Read the posts in this and other threads and forums, view the before/after exampls in many of the threads, and form your own opinion as to what will meet your needs. It is, after all, your tapes, your time, your money, and if doing this for others your reputation.

You can always try cheap, decide the results draw a vacuum, and then do it again the better way (provided the tapes have not been trashed by a bad VCR on the first try).

lordsmurf 07-17-2019 03:28 PM

Quote:

Originally Posted by dpalomaki (Post 62590)
But it all depends on how good is good enough for you

That statement makes it seem as if TBC is an optional item just to make tapes look better, but that's really not accurate. Analog signals, VHS especially, have flaws. Really, really bad flaws. CRT TVs were more forgiving, also being not-precise analog technology. But when you try to digitally acquire signals, precision is expected and required. And those not-precise/flawed signals cause problems. Not just visually, but in terms of being capture-able/ingest-able at all. TBCs fix the timing errors (the signal flaws, the imprecisions, the imperfections).

It's not an optional item. :no2:

Yes, there are some conditions where you can make passable capture/conversions without TBC, but it's not quality. There will be flaws. And again, some conditions, not all -- too many people think they're the exception, rather than the rule. Avoiding TBC is unlikely for most.

TBCs is a necessarily evil, a costly item. Always was, always will be. I remember grumbling when I had to buy my first TBC in the 90s. Then I saw what a difference it made. I grumbled less. :laugh:

dpalomaki 07-17-2019 04:54 PM

Maybe I should have said; "How bad is good enough for you."

murfmurfmurf 07-19-2019 10:04 AM

Quote:

Originally Posted by lordsmurf (Post 62591)
TBCs is a necessarily evil, a costly item. Always was, always will be. I remember grumbling when I had to buy my first TBC in the 90s. Then I saw what a difference it made. I grumbled less. :laugh:

Yes, but now they're approaching the realm of "unreasonably expensive". The only decent ones for home video capturing are now $500 and up, and that price is only going to get higher. We're all going to be very screwed in the near future if no other new ones are brought to market.

If a TBC is so necessary, then we should come up with a project for people to be able to build their own TBC. This thread lists a number of projects that do just that, and I know a number of people here are experienced in electronic design. Perhaps you could solicit some help from the people here?

lordsmurf 07-19-2019 11:31 AM

Quote:

Originally Posted by murfmurfmurf (Post 62623)
Yes, but now they're approaching the realm of "unreasonably expensive". The only decent ones for home video capturing are now $500 and up, and that price is only going to get higher. We're all going to be very screwed in the near future if no other new ones are brought to market.

If a TBC is so necessary, then we should come up with a project for people to be able to build their own TBC. This thread lists a number of projects that do just that, and I know a number of people here are experienced in electronic design. Perhaps you could solicit some help from the people here?

TBCs were always in the $500+ range (in 2019 dollars, or $400 in 2000-2005 dollars).

- Broadcast/rackmounts were $1k+ (not desirable anyway).
- A few studio-grade TBCs (from same makers as the broadcast) were in the $500-$1k range.
- The prosumer were almost all in the $450-750 range.
- The one exception was the Taiwanese maker Cypress, which had some sub-$400 prosumer units. Unfortunately, in an apparent effort to keep costs down low, actually reducing price over time (negative inflation), flawed chipsets were used, making the unit useless.
- Note that Cypress also had studio-grade units in the $500-$1k range.

The idea that a homemade TBC could be made cheaper than a mass produced unit, and be of equal quality, is flawed. And here's an example of why...

Most folks here don't know that my other hobby is action figures (which should make sense once they realize the reason I got into video was due to cartoon collecting). Not just action figures, but customizing figures. That takes a lot of time, and generally costs 10x+ as a mass produced figure. Yet the newbie misconception is that a custom figure should cost the same as the mass produced figure. So what happens is you'll find people on forums/Facebook whining about customizers "charging too much" when in reality they generally break even, and do it mostly as 1st-run practice for the custom kept for their own collection.

Another issue with TBCs is that it's not just about electronics know-how, but availability of parts. Realize that DataVideo and Cypress both left the TBC market specifically because the needed chips were discontinued. So that's a major problem preventing future TBC production.

There was a small window, years ago, when new TBCs were still available (though mostly EOL and NOS only), and used TBCs sold for the standard 50-75% new value. So, for example, you could get a TBC-1000 for $300 or so. But that didn't last, and was never going to last. It also coincided somewhat with the recession and post-recession market (2009, early 2010s), where there is a fire sale type of mentality (sell for whatever you can get, need cash now), combined with less buyers.

The biggest problem with buying a TBC is user mentality. Understand that it's probably not a "forever purchase" for most people. You don't buy it, use it, and then stick it in a box in the closet. It's a "project purchase". Buy it, use it, resell it. In the end, it's essentially a rental. You'll get most, or even all, of your money back on it.

Mazen_Khaddaj 07-28-2019 01:22 PM

It depends on where you live. It’s really hard to find any where I live.

lordsmurf 07-31-2019 05:35 AM

Quote:

Originally Posted by Mazen_Khaddaj (Post 62861)
It depends on where you live. It’s really hard to find any where I live.

This is why I ship worldwide, when offering TBCs in the marketplace. :wink2:

heavymod 08-20-2019 07:13 PM

So are rackmounts like the JVC SA-T100 no good? I.DEN IVT-7 ?

I'm assuming Fortel Y-688 is useless.


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