What are the different types of external TBCs?
 

Hi there,

I know what a tbc is when it comes to the ones connected to vcr like datavideo models or av toolbox ones.

Recently, I saw some "weird" TBC/frame synchronizers on ebay that has a different input/output ports than the usual rca connectors used so I was wondering for what purpose are those used and is there a convertor to use them with a VCR?

Here are the ones I'm curious about:

Miranda ASD-221i
- https://www.ebay.com/itm/183878786490

Beck TBC RMT-2 Frame Synchronizer
- https://www.ebay.com/itm/143434190378

Zaxcom video HCP400 REV B TBC Time Base Consoles
- https://www.ebay.com/itm/122357873892

- backup screenshots of the 3 listings in case the ebay link dies: https://imgur.com/a/tNfn5sR

I would appreciate if someone can explain a bit about those :)

Thanks in advance

The Miranda is a modular card that goes into a rack mounted broadcast facility chassis. It would work in concert with a system for acquiring and decoding and correcting an RF signal into something that could be recombined with other video signals at the production facility then re-modulated and broadcast.

It is not suitable for the home user.

The Beck TBC RMT-2 is a "remote console" it is not a TBC. Its meant to bring the controls away from a rack mounted chassis so that the controls could be bolted into a desk or console like on the Star Ship Enterprise for centralized management.

Its not what your looking for and really is of no use without the actual time base correction equipment and system that hosts it in a big rack.

The Zaxcom video HCP400 REV B TBC Time Base Consoles is not a TBC. It is also a remote console where the control cables from the TBC rack mounted system are brought out and plugged into a central dash for the producers to manage the equipment.

Its also not what your looking for and of no real use.

There is a vast difference between Consumer / Home user "stand alone" TBC devices like the datavideo or avtools boxes and the Gigantor sized huffing and puffing TBCs as big as a house that fit in the broadcast production facilities.

There are probably more of those 1950's TBC systems laying around in warehouses just never carted off to the landfill that will continue to show up on eBay. Their smaller "remote consoles" are closer in size to the "tiny" datavideo and avtools boxes from the turn of the Century. So its easier to confuse them with the Huge dinosaurs the rear cables were meant to lead back to.

Honestly there are only a small hand full of Consumer grade models and they were only made in the mid to late 1990's before they started incorporating them into both high end VCRs and DVD recorders.

The stand alone models were never popular due to cost and cable complexity. For most people casually doing transfers the VCRs and Tapes were still in good condition and TBCs were mostly an expensive after thought. Its only much later when things began to rot and VCRs were run to death and began to fall apart that TBCs got popular.

After VCRs stopped being made, things exacerbated.. and TBCs partnered with rickety VCRs .. achieved near mythological status.. and prices shot to the moon.

Some PC capture cards also incorporated TBC circuits and processors into their design, making the stand alone models redundant.. but people still trade the stand alone TBCs. Mostly because those cards are also not well documented and the ones that are known are closely held and not discussed very much.

To add a bit of general information. "Frame Synchronizers" are used to bring independent video signals to a common time base (i.e., each frame and scan line in the signals starts at the same time). This is necessary for switching between two or more signal sources, as is done in broadcast situations or in linear video editing of input from more than one tape player. If the video sources are not synchronized you get a glitch at the switching point.

Many frame synchronizers expect good input video signal and thus may not prove effective in correcting time base errors within a sloppy input signal.

At the generally affordable consumer/prosumer level video mixers (e.g., the Videonics MX-1) typically contain frame synchronizers. Because they rebuild the sync signals the process can clean up weak sync and Macrovision on the input video signal, provided that the device can read the input signal - and that can be problematic if the input signal is really bad.

I just want to add that in general a frame synchronizer should always follow a TBC, In capture devices they can add or drop frames to keep the audio in sync with the video.

With very few exceptions, what you see on eBay is mostly crap. It's a video dumping ground more than not.
- Many sellers lie; sometimes knowingly, sometimes not.
- Many buyers are newbies, suckers, also don't know what they're buying, until it's too late.

Almost all of that stuff comes from estate sales, warehouse/storage auctions, etc. It's been kept in horrible conditions. I recently acquired something, for TBC research, that smelled like a mushroom farted. The smell will saturate a room worse than cigarettes.

You must be careful.

All of that stuff linked to is cast-off garbage, no real use. Not to broadcasters or studios. Not to anybody conveting consumer analog tapes.

At best, that Miranda card may be useful for TBC R&D. The others should probably be recycled for precious metals.

The prices are laughably ridiculous. :laugh:

Wow, Thanks a lot guys for the good answers and details specially the long detailed explanation by jwillis84. I really appreciate your time guys :)

Also, I posted this in another thread too, but since it's the same topic, may I ask you guys what you think of those:

Prospec japanese DVE TBC devices
https://translate.google.com/transla...omparison.html

Is this another "fake/commercial" usage of the term TBC?

I answered the other thread.
But again: Yes, that appears to be bastardized use of "TBC". What I see there is NOT a TBC whatsoever, just one of those cheap "copy protection remover" devices. I actually saw some eBay auctions (not current) than specifically disclaimed that it was not a TBC.