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FOR-A FA-300P phase controls

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Maarten Fransen
FOR-A FA-300P phase controls
on Oct 17, 2016 at 9:13:07 am

Hello,

I've recently aquired a perfectly working for.a FA-300P Timbease Corrector to digitize my VHS tapes. Unfortunately no documentation came with it. I wonder where the controls for Video Phase, SC phase and H phase are for?


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James Hauge
Re: FOR-A FA-300P phase controls
on Oct 17, 2016 at 7:42:45 pm

This might help, it's the user manual for the next model (or two) up from what you got... It should be able to answer most of your questions about it and what it does/can do...

http://www.for-a.com/products/fa370p/FA370np-E-E1R4.pdf

Sorry, that's the best I got for you...


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Tom Matthies
Re: FOR-A FA-300P phase controls
on Oct 18, 2016 at 4:24:42 pm

If you aren't Gen-locking the unit to an external reference, they really don't do anything.

Not my monkeys. Not my circus.


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Bob Zelin
Re: FOR-A FA-300P phase controls
on Nov 15, 2016 at 2:46:51 pm

back in the stone age of standard def video, and analog video switchers, all products that needed to go into the video switch needed to be genlocked to a house black generator (like an AJA GEN10). So you would put your horrible VHS machine into a For A Frame Synchronizer (if it's a TBC and not a Frame sync, it will do nothing for your VHS machine) - and this would replace the entire sync interval of the unstable VHS playback (same with Sony 3/4" Umatic tapes).

So now your VHS machine is going into a switcher, but it needs to synchronize with other video sources (like other VTR's and cameras). You would own a waveform monitor and vectorscope (in those days typically from Tektronix or Leader), and put your black reference signal into those as well. You would expand the Tektronix Waveform monitor to see the sync interval, and switch (or dissolve) between your sources (like the For A) - usually done against the internal black signal or color bars on the switcher. You now turn the H Phase on the For A so that the sync signal stays in one place. If you did not do this, you would get a horizontal shift when you switched or dissolved between sources (like a Camera and the For-A). The SC phase is subcarrier phase. If that was off, you would get a color shift when you switched or dissolved between sources - you would look at the burst signal on the Vectorscope to make sure that when you went from black (your reference) to your For A, the SC would not move (the burst would not move) on the scope. When they matched, there would be no color shift.

Now, for your last control - Video Phase - this adjusted your color phase. So when you lined up your SC burst with the SC phase control, and you played back color bars on your tape (every pro tape had color bars at the head) - you now adjusted the dots of the color bars on the vectorscope so that all the colors lined up in the dots - you use the video phase control to do this.

There were other controls too - video level, black level and chroma level. All adjusted using color bars looking at your scopes, to make the signal correct.

Every editing session was an ordeal - that's why editors used to get paid a lot of money.

Bob Zelin

Bob Zelin
Rescue 1, Inc.
bobzelin@icloud.com


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Tom Matthies
Re: FOR-A FA-300P phase controls
on Nov 15, 2016 at 3:38:39 pm

It's sad, Bob but most of the people reading this right now have no idea of what you just said. "Timing"...what's that mean? I used to keep the timing in my suites really "tight" but, in so many ways, it just doesn't matter anymore. I was telling one of the crew guys how we used to register tube cameras back in the day and his response was "But why would you even need to do this?"
It's a whole different world now...

Not my monkeys. Not my circus.


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