LM1881 Sync Separator

[zedrein]

Thankfully mine came yesterday, so hopefully I am all ready to try and get RGB from my NTSC SNES to my Commodore 1084 monitor (1084 pinout http://pinouts.ru/Video/C1084a_pinout.shtml)

I just have a few questions about using the chip:

1.) Since I just found out that I have to use a 0.1uf cap in series when connecting composite video to the chip, which side (- or +) do connect to the chip itself?

2.) I'd imagine I simply just solder the cap directly onto the leg (pin #2) of the chip--if I am wrong, please tell me.

I am working with a limited amount of space in my DIN-6 connector so hopefully I don't have to cram more than just the chip into there.

If there are any more things I need to note about using this chip, please tell me--also, if there is any other things I need to know about getting RGB from my SNES please let me know. Thanks for the help.



Is this an accurate diagram? (PLEASE IGNORE LEFT+RIGHT STEREO LINES)

For reference, here is the Commodore 1084 pinout as seen in the diagram: http://pinouts.ru/Video/C1084a_pinout.shtml

[viletim]

Why do you feel the need to create a new topic for each of your posts? Try 'reply' next time.

Thankfully mine came yesterday, so hopefully I am all ready to try and get RGB from my NTSC SNES to my Commodore 1084 monitor (1084 pinout http://pinouts.ru/Video/C1084a_pinout.shtml)

I just have a few questions about using the chip:

1.) Since I just found out that I have to use a 0.1uf cap in series when connecting composite video to the chip, which side (- or +) do connect to the chip itself?

Best to use a non polarised capacitor. Plastic, ceramic, etc. But if you've already gone an bought something weird like a 0.1µ electro cap then you should connect the +ve to the chip.

2.) I'd imagine I simply just solder the cap directly onto the leg (pin #2) of the chip--if I am wrong, please tell me.

Yes.

I am working with a limited amount of space in my DIN-6 connector so hopefully I don't have to cram more than just the chip into there.

If there are any more things I need to note about using this chip, please tell me--also, if there is any other things I need to know about getting RGB from my SNES please let me know. Thanks for the help.

PAL or NTSC?

[zedrein]

^ Thanks for the replies! As I noted before, it's a NTSC SNES, which I already know requires 3 220uf caps on the RGB lines. I already got those caps, although I think they're electrolytic, I hope they'll be fine.

I've put together a little picture so I can get a better idea of what this will actually look like:



Please don't judge based on the crudeness!

[viletim]

^ Thanks for the replies! As I noted before, it's a NTSC SNES, which I already know requires 3 220uf caps on the RGB lines. I already got those caps, although I think they're electrolytic, I hope they'll be fine.

I've put together a little picture so I can get a better idea of what this will actually look like:



Please don't judge based on the crudeness!

That's a pretty sparse diagram. Did you leave out the Vcc (+5v) and ground connections to the chip intentionally? Other than that it looks ok.

I like to put a 75 ohm (value not critical)  between the video input (ie. the end of the cap not connected to the chip) to keep the video driver happy. It's not required in most cases though.

[zedrein]

That's a pretty sparse diagram. Did you leave out the Vcc (+5v) and ground connections to the chip intentionally? Other than that it looks ok.

I like to put a 75 ohm (value not critical)  between the video input (ie. the end of the cap not connected to the chip) to keep the video driver happy. It's not required in most cases though.

I guess I learn something new everytime I log on to gamesx--so now I need to bring out the +5 volt wire from the SNES and the Ground to the Lm1881? I suppose that makes sense considering that this little thing needs power and all, I suppose I just assumed that I could plug in the comp video line and magically get composite sync.

Also concerning the ground wire: The SCART diagram specifies the only ground wire I have as "audio ground" Will I be able to distribute this ground into video, 2 audio, and now the LM1881? What would that entail? Do I need to put even more electronic components between the ground/+5 volts wires and the chip? Perhaps I'll make another (more complete) drawing and you can pick it apart for me.

(SEE TOP POST)

For reference, here is the Commodore 1084 pinout as seen in the diagram: http://pinouts.ru/Video/C1084a_pinout.shtml