I've added a link to S39 so I can get colour composite for recording video while using RGB for the main display. I did a quick test yesterday with a paperclip and I was getting a flickering colour/black and white image (bad connection I thought), but now I've connected it properly I'm not getting colour. I did briefly get a flickery image, but it's back to black and white again.
I've done some research, and it sounds like twiddling VC1 may help. I don't want to mess up my RGB, though I think that may be a totally isolated signal and not affected by VC1, though I would like to check first.
Is it safe for me to twiddle the pot while switched on without any worries about making things worse?
Will changing VC1 fix my colour problem?
Will changing VC1 fix my colour problem?
"The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties!" - Jack Howitzer, GTA V
Re: Will changing VC1 fix my colour problem?
Yes, VC1 only affects the composite output, has no effect at all on RGB.
It's quite likely to be the cause of intermittent colour/monochrome.
It's quite likely to be the cause of intermittent colour/monochrome.
Re: Will changing VC1 fix my colour problem?
Thanks.
It didn't work. I got an occasional flicker, but nothing useful.
Unless there's a faulty chip or something, I may have to do the RF Composite mod if that's got a chance of being any better.
It didn't work. I got an occasional flicker, but nothing useful.
Unless there's a faulty chip or something, I may have to do the RF Composite mod if that's got a chance of being any better.
"The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties!" - Jack Howitzer, GTA V
Re: Will changing VC1 fix my colour problem?
I think I'll just forget about that idea and get a Scart splitter. It's £50, but will split the RGB for me. That should work well.
"The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties!" - Jack Howitzer, GTA V
- maniacminer
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Re: Will changing VC1 fix my colour problem?
I assume you mean £5? Do you have a device for recording that takes an RGB signal directly? To get colour, you will need to add some extra capacitance in location C51 like 10pF or more if there is a capacitor already fitted at this location.
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Re: Will changing VC1 fix my colour problem?
No, £50 (including postage).
All the others are male in to 2 x female out. I have one of those.
I got a gender changer, but that doesn't swap the in/out pins. The only way into it was to destroy the case so I didn't bother. I tried swapping the pins on one of the the Scart cables but ended up getting the BBC B going to the tv, then BBC 1 going to my capture card!
I ordered a proper active buffer professional one to stop me having problems and give a good picture. I can also use it with my other computers, as they mostly have Scart outputs.
I thought about changing the capacitor, but with the amount of problems I'm having with it at the moment I just want a quick and easy fix that I know will work.
All the others are male in to 2 x female out. I have one of those.
I got a gender changer, but that doesn't swap the in/out pins. The only way into it was to destroy the case so I didn't bother. I tried swapping the pins on one of the the Scart cables but ended up getting the BBC B going to the tv, then BBC 1 going to my capture card!
I ordered a proper active buffer professional one to stop me having problems and give a good picture. I can also use it with my other computers, as they mostly have Scart outputs.
I thought about changing the capacitor, but with the amount of problems I'm having with it at the moment I just want a quick and easy fix that I know will work.
"The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties!" - Jack Howitzer, GTA V
- 1024MAK
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Re: Will changing VC1 fix my colour problem?
Ideally for a SCART splitter, you want an active device that electronically amplifies/buffers the signals so that the signal amplitude is not effected.
That means that it has to have a power source.
VC1 only affects the colour component of the compositive video output and the TV/RF/UHF output. Even when VC1 is not adjusted correctly, you should still get a monochrome video a signal.
Mark
That means that it has to have a power source.
VC1 only affects the colour component of the compositive video output and the TV/RF/UHF output. Even when VC1 is not adjusted correctly, you should still get a monochrome video a signal.
Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki - for answers to many questions...
Fault finding index • Acorn BBC Model B minimal configuration • Logic Levels for 5V TTL Systems
BeebWiki - for answers to many questions...
Fault finding index • Acorn BBC Model B minimal configuration • Logic Levels for 5V TTL Systems
Re: Will changing VC1 fix my colour problem?
Yes it's a proper active one with power.
I do get a monochrome signal. I didn't know how much to turn it. It seems to keep going, but I didn't know if it actually unscrews, or if there is only 360 degrees of positions.
Hopefully the splitter will arrive today and I can try that.
I got an Oscilloscope yesterday, so I might be able to work out what's wrong if I needed to, though I'm a total beginner with it.
I do get a monochrome signal. I didn't know how much to turn it. It seems to keep going, but I didn't know if it actually unscrews, or if there is only 360 degrees of positions.
Hopefully the splitter will arrive today and I can try that.
I got an Oscilloscope yesterday, so I might be able to work out what's wrong if I needed to, though I'm a total beginner with it.
"The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties!" - Jack Howitzer, GTA V
- 1024MAK
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Re: Will changing VC1 fix my colour problem?
VC1 is a capacitor trimmer, there are no end stops but rotating it further than one turn (360 degrees) just gets you back to where you were.
Most have a metal vane that are half of a circle and it's the position of this that is moved as you rotate the adjustment screw.
Mark
Most have a metal vane that are half of a circle and it's the position of this that is moved as you rotate the adjustment screw.
Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki - for answers to many questions...
Fault finding index • Acorn BBC Model B minimal configuration • Logic Levels for 5V TTL Systems
BeebWiki - for answers to many questions...
Fault finding index • Acorn BBC Model B minimal configuration • Logic Levels for 5V TTL Systems