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Genlocking
I am taking over my church’s media department. We are planning on doing a major update in the near future once we move into our new facility but in the meantime I have to use what I inherited. A JVC KM-1200 Color Special Effects Generator, two Ikegami HC-340A Cameras with two Ikegami MA-200 Multicore Cable Adaptors. The equipment was purchased brand new a hundred years ago and since then the operators before me didn’t take as much care of it as they should have. Any way, everything was working fine until recently. Right before I came along mysteriously the cameras became “ungenlocked” if that is a word. I can’t get a clear transition between the two camera and I am lost. I know the setup works because we used this same setup for several television programs, problem is the people who initially set it up are no longer around.
From the switcher there are three BB outputs, one VB/BB output, one sync. Also there are 4 composite inputs with the 5th one being a optional 5/Genlock. The CCUs have a gen-lock in and out, and a sync output. I am trying to go from one of the BB outputs ont the switcher into the Genlock input on CCU 1 and from the Gen-lock output on CCU 1 into the Genlock input on CCU 2. I get a steady image on ccu 2 although the color is wavy and RGB pulsating but on CCU 1 the image has horizontal scroll effects going on. Input B on the switcher is in disarray Input A row is as described above.
Ive tried several combinations to no avail. Gen-lock/5 on switcher to Gen-lock in on CCU and sync on CCU. VB/BB on switcher to Gen-lock in on CCU and sync. Can anyone give me some advice besides trash everything. Not really an option yet, though I am fighting to do so but until then I have to make this set up work again temporarily.
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5 Replies
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do you have a waveform monitor to see if you actually have a working black signal ? That’s what test equipment is for . No black – no genlock. You have old equipment – guess what – old equipment breaks.
A modern Black generator can be had from AJA or Blackmagic brand new for about $300, but if your switcher is broken, a working black gen will not help you. Is all of this stressful – of course it is – this is what it is always like dealing with technology. Including your home computer, and CEL phone. Things get outdated, things break.
1) get a waveform monitor to see if you have a working black signal
2) buy a new black generator
3) perhaps your switcher has failed. Today, it is very cheap to buy a new video switcher – Roland makes composite video switchers that are under 2 grand, and if you go HD-SDI (whcih you won’t because your cameras are not hd cameras) the Blackmagic ATEM is only $1000, and can do what you want.And you will find that trying to get someone to “fix it” won’t work either, because today’s labor costs will cost as much as new equipment. Unless you can find another church volunteer that is an engineer.
Bob Zelin
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Thank you Bob. I will get a waveform monitor to test the black. As soon as possible I am planning on replacing the old mixer with a newer one, but until then I’ve got to work with what I have. I’ve been placing the gen-lock cable in different slots on the KM-1200 the BB, the Sync and Gen-lock/5. I can get one CCU to become steady in Gen-lock/5 but when I try to loop from gen-lock out on the CCU to the Gen-lock in on the other, I can’t get a clear picture. So this week I’m going to check the signal in the Waveform monitor.
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every step of the way – every cable, you use the waveform monitor. Even if you don’t know how to read it – you can see the difference between a straight line and some sort of signal. As you go from unit to unit, when you get a straight line, there is no black, and you have a bad cable.
Bob ZElin
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I know I might be a bit late, but… When looping a signal, especially on older devices, you have to make sure that you use a 75Ω BNC terminator on the last loop O/P in the chain. This might be the reason you are experiencing trouble.
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No it’s not too late thank you. I had someone look at it, and it seems I had just what you are saying. A channel was open that should have been closed.
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