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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: SuperPlay on November 25, 2012, 03:34:52 AM

Title: PAL RGB horizontal shift
Post by: SuperPlay on November 25, 2012, 03:34:52 AM

Hi Folks

I have the infamous issue with horizontal shift (where on a CRT the RGB image is shifted to the left slightly due to composite sync)

Has anyone made-up one of these?

http://nfggames.com/forum2/index.php?topic=4436.0

http://www.sega-16.com/forum/showthread.php?21131-RGB-Horizontal-%28left-shift%29-correction-circuit-and-layout


Is it worth trying a Composite Sync Stripper (LM1881) ?

http://www.mmmonkey.co.uk/composite-sync-stripper-lm1881/


Thanks

Title: Re: PAL RGB horizontal shift
Post by: HercTNT on November 25, 2012, 03:56:58 PM

Professor put up a simple circuit showing how to build the sync stripper. It worked for me, give it a go.

Title: Re: PAL RGB horizontal shift
Post by: SuperPlay on November 26, 2012, 08:20:56 AM

I have done a bit more digging and have identified that this seems only to be an issue with composite sync and PAL TV sets.  Sets that support PAL+NTSC (or just NTSC for that matter) do not seem to have the issue, many of these sets also allow you to set the RGB sync from PAL to NTSC in the menu.

I will give the sync stripper a go as suggested and I will see if I can find anyone that has built the PAL Horizontal sync fixer circuit.

Title: Re: PAL RGB horizontal shift
Post by: fraggore on November 28, 2012, 06:16:36 AM

most of the old crt's pal that is, suffer this you could just try and fined the service menu and adjust the screen that's what i have done.

Title: Re: PAL RGB horizontal shift
Post by: SuperPlay on November 29, 2012, 07:45:21 AM

The CRT had no service menu.  However I opened it up and manually changed the pots :-)

Title: Re: PAL RGB horizontal shift
Post by: fraggore on November 29, 2012, 06:59:44 PM

all good then tidy

Title: Re: PAL RGB horizontal shift
Post by: SuperPlay on November 29, 2012, 09:32:09 PM

Quote from: fraggore on November 29, 2012, 06:59:44 PM

all good then tidy

Sure is :-)