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NFG Forums => RGB + Video Discussions => Topic started by: Whacka on June 12, 2012, 04:46:58 PM

Title: LM1881 not working - HSYNC needed?
Post by: Whacka on June 12, 2012, 04:46:58 PM
Hey there, I just built a sync separator circuit with an LM1881 for my Saturn.
( SCART -> Audio/RGBHV -> BNC )
Unfortunately it's not working  :'(
I'm guessing that my TV doesn't support CSYNC because the VGA output from my Dreamcast works well.

See video;

https://www.youtube.com/watch?v=N-DaUYMD1fQ (https://www.youtube.com/watch?v=N-DaUYMD1fQ)


Can anyone tell if this is the problem? I have a Sony KV-HR32M31 TV.
Also I read someone that you can use logic gates to get a working HSYNC signal. Can someone recommend me a cheap, common IC that'll do what I need?
Title: Re: LM1881 not working - HSYNC needed?
Post by: RGB32E on June 16, 2012, 05:58:15 AM
That's one beast of a TV!  You might have better success using an EL1883.  It only comes in a SOIC package, so you'd likely need to get a DIP adapter to mount this to for use (legs on SMD ICs tend to break much easier than PDIP).

http://www.intersil.com/en/products/audiovideo/video-ics/video-sync-separators/EL1883.html (http://www.intersil.com/en/products/audiovideo/video-ics/video-sync-separators/EL1883.html)

http://www.hoylen.com/articles/tech/sony-kvhr36m31/Sony-KV-HR36M31-Operating-Instructions.pdf (http://www.hoylen.com/articles/tech/sony-kvhr36m31/Sony-KV-HR36M31-Operating-Instructions.pdf)

OR... just save yourself the trouble of building a circuit and get a Sync Strike:
http://shmups.system11.org/viewtopic.php?f=6&t=37285 (http://shmups.system11.org/viewtopic.php?f=6&t=37285)
Title: Re: LM1881 not working - HSYNC needed?
Post by: Segasonicfan on July 08, 2012, 08:01:57 AM
yep, had this problem before.  El1883 will solve all your problems, and SOIC is easy to solder with a little practice.  There's also the ISL59885 that does the same thing with some added auto-syncing touches.