GBS 8220 CGA to VGA scaler question

PCB problems and fixes
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pixeljunkie
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GBS 8220 CGA to VGA scaler question

Post by pixeljunkie »

Has anyone modded these to get rid of the odd jitter that happens with them? Just curious if there is something more I can do.
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Rossyra
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Re: GBS 8220 CGA to VGA scaler question

Post by Rossyra »

I've read they are a lot more stable if you can run them around 4.5v. Never been arsed to try because I'm all 15ked up now, but mine jittered like a mofo before.
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pixeljunkie
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Re: GBS 8220 CGA to VGA scaler question

Post by pixeljunkie »

Rossyra wrote:I've read they are a lot more stable if you can run them around 4.5v. Never been arsed to try because I'm all 15ked up now, but mine jittered like a mofo before.
interesting, I'll have to give that a try.
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trmatthe
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Re: GBS 8220 CGA to VGA scaler question

Post by trmatthe »

I had an LMxxxx something which would extract the sync and I tried wiring it between the PCB output and the upscaler input which did seem to help. I can try to find the p/n if you like. I'm tri-synced now so don't use the upscaler and my eyes thank me :awe:
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Hewitson
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Re: GBS 8220 CGA to VGA scaler question

Post by Hewitson »

LM1881?
crunchywasp wrote:During your visit you could reverse his evil honey trap and tell him you're a bit uncertain about spending an hour inside his box
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Spectre
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Re: GBS 8220 CGA to VGA scaler question

Post by Spectre »

Rossyra wrote:I've read they are a lot more stable if you can run them around 4.5v. Never been arsed to try because I'm all 15ked up now, but mine jittered like a mofo before.
That's very useful info, think I'll buy one of these;

http://www.ebay.co.uk/itm/280754914974
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trmatthe
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Re: GBS 8220 CGA to VGA scaler question

Post by trmatthe »

Hewitson - that rings a bell, but there are also a trillion op-amps in the LM range so I wouldn't buy one without confirmation as you may just end up with some weird gain opamp :) If anyone is interested I can dig it out.
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kazuo
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Re: GBS 8220 CGA to VGA scaler question

Post by kazuo »

I've noticed that my scaler jitters as well from time to time. I have two, so more than happy to use one as a guinea pig if anyone has any ideas.
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