Author Topic: MOD GUIDE - Universal RGB-to-YPbPr/Component Circuit & Mod [8/24/2014]  (Read 19622 times)

turbokon

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #105 on: May 06, 2013, 03:00:48 AM »
Looks like I got the component mod working right. I used 500ohm for R2 and 10kohm for R4 & R6 and everything else per thesteve design. With the pots I can adjust the red & blue to my liking. I've been at this for a few weeks. Time for me to close it up:)
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #106 on: May 08, 2013, 10:10:01 PM »
So, I finally did this mod on a system I had on hand and man do I have to say it is not for the faint of heart. It just took a really really really long time to build this circuit. It took me so long I have decided I will never do this mod again unless there are some premade PCBs for it cause it definitely was not worth the time to have the improved picture quality. Then again, I still prefer to use a CRT TV. So I suppose if all you own are Flat screens then maybe your will power to do this mod would be greater?

On the positive side it does look great.

turbokon

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #107 on: May 13, 2013, 10:21:12 AM »
I finally got my TG16 all closed up with the component mod. All I can say it looks fantastic on an HDTV now:)



Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #108 on: June 13, 2013, 08:19:17 AM »
I am having an issue with Jailbars. I installed the two suggested caps for the jailbar fix and it doesn't seem to do anything to help. The system I put the mod in is a US TG16. The games you can see them the most in is anything with blue background. So bomberman title screen or JJ and Jeff work great for testing. Anyone have any suggestions?
« Last Edit: June 13, 2013, 08:24:55 AM by Keith Courage »

NightWolve

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Re: MOD GUIDE - Jailbar Reduction Techniques/Suggestions
« Reply #109 on: June 14, 2013, 04:29:40 PM »
I am having an issue with Jailbars. ... Anyone have any suggestions?


I got two for ya:

1) From steve: Ground your mod video circuit (be it a RGB amp or our new YPbPr mixer, etc.) as close as possible to the 6260 chip - pins 55+56. You can bridge them as they're both ground for easy soldering of a wire! Here's a nice video I remembered that I'm gonna link in the OP:


I've also updated the Jailbar Guide photo to help. :)



2) You familiar with twisted pair wires ?? That was a basic, cheap way to help reduce interference as the ground/negative wire wraps around the signal wire, etc. The next step up, the better way was a coax design, where the ground is sheathed/braided wiring that completely surrounds the signal core wire inside. If they use aluminum wire, they'll even wrap it with solid aluminum foil. If it's just copper, it'll be just braided copper, etc. Anyhow, point is, if you're willing to do the grunt work, you can try switching from single, solid wires to dual ones that include ground, just like the very RCA cabling that is used for Composite/Component on the outside, etc. The best would be the thinnest copper ones you can find. Problem is they'll be bigger than the single wires you're using now... Solid twisted pair wires not so much, but they're not as good at interference reduction. Note, no guarantees here with this idea, but just a suggestion...

Other than that, I can't think of too much else from what I've read around here. There was talk about using more shielding over chips and stuff somewhere though. If you were willing to go that far, that is, etc... But yeah, I'd try the first basic suggestion unless you already tapped those pins for ground.
« Last Edit: June 14, 2013, 10:59:11 PM by NightWolve »

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #110 on: June 16, 2013, 01:40:40 PM »
I'll try taking ground directly from the 6260 Chip first and let you know what happens. Thanks for the info.

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #111 on: June 16, 2013, 05:38:41 PM »
Not sure how or why but using those pins for ground off of the HU6260 chip actually made my jail bars worse :(

turbokon

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #112 on: June 16, 2013, 05:44:39 PM »
Keith, how did you tapped the rgb & synch for the tg16? The first tg16 I tapped from expansion bus and the jail bars wasn't that apparent. I just did another tg16 and I tapped it directly from hu6260 and jail bars are more noticeable.
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #113 on: June 16, 2013, 05:50:43 PM »
I tapped everything directly from the HU6260 chip. Maybe I should try the expansion bus instead.

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #114 on: June 16, 2013, 06:20:52 PM »
I just tapped from the expansion port instead and man what a difference. The Jail bars look 10 times better. They still exist but now you have to look for them instead of them staring you right in the face.

I still wish I could get them to go away completely but I guess this is better than the way it was. Still very noticeable on blue backgrounds.

Can anyone confirm that jail bars are not present on DUOs? Maybe it's a US Tg16 issue for whatever reason?
« Last Edit: June 16, 2013, 08:01:46 PM by Keith Courage »

turbokon

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #115 on: June 16, 2013, 11:56:54 PM »
That'a good news, I will redo this tg16 and tap rgb from
 Expansion port.

Yeah, the jail bar is eliminate with the fix for a duo, at least I didn't notice it.
« Last Edit: June 17, 2013, 06:07:00 AM by turbokon »
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

NightWolve

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #116 on: June 17, 2013, 06:04:52 AM »
I just tapped from the expansion port instead and man what a difference. The Jail bars look 10 times better. They still exist but now you have to look for them instead of them staring you right in the face.

I still wish I could get them to go away completely but I guess this is better than the way it was. Still very noticeable on blue backgrounds.

Can anyone confirm that jail bars are not present on DUOs? Maybe it's a US Tg16 issue for whatever reason?

Oh wow, thanks for the experimenting. Hmm, so tapping ground close to or at the chip is questionable then. I wonder if shielded wires like I mentioned would make a difference. That'd be the other thing left to try besides that shielding idea (those plastic coated pieces of aluminum or whatever they cover chips with, etc.).

So to review, with steve's 2 capacitor idea and tapping the signals at the expansion port, jailbar reduction is pretty good now ?? Is your +5 V supply taken right from the regulator BTW ??
« Last Edit: June 17, 2013, 06:08:36 AM by NightWolve »

thesteve

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #117 on: June 17, 2013, 07:43:35 AM »
sounds like you may have a bad ground to the chip itself

turbokon

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #118 on: June 17, 2013, 07:55:08 AM »
Is there a way to check whether you have a bad or good ground with a multi meter obviously other then the continuity check??
Turbo fan since 1991 after owning my first system.

Check out my website:)
www.tg16pcemods.com

Keith Courage

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Re: MOD GUIDE - Cheap NEC Component (YPbPr) Video Mod [3/20/2013]
« Reply #119 on: June 17, 2013, 08:29:59 AM »
If there is a bad ground on the chip itself couldn't I just take a wire from the ground on the board and run it to pin 55&56 to fix the problem?