Amping the sync signal?

[MNKyDeth]

Ok, so I sold one of my friends that is local one of my repaired Duo's. He uses a BVM and the system works great plugged straight into it. Composite and RGB work without issue.

This system is a Duo-RX and it has the tg16pcemods RGB amp in it.

He bought a Euro scart splitter and when hooking up the console through the splitter he loses the sync signal. The consoles screen shows up on the BVM but it is sliding around on the screen as he says.

So... do I just need to amp the sync signal? If so I know the tg16pcemod AMP's use two chips. One chip amps green and blue the other chip amps red. Could I use the chip that is amping red to also amp the component video for sync or Sync from pin 44?

If there is no "good" solutions to this I will just have to tell him to plug it straight in. But I want see if there is a solution first. Thanks for any input.

[mickcris]

I think he maybe needs to get a switch not a splitter. those arent upposed to be used like a switch if that's what he's trying to do. What is he doing with the splitter exactly?

He shouldn't need to split the signal as the bvm passes rgb through it. Can just hook whatever up to the bvm output.

[MNKyDeth]

Ahh yes, it is a switch, I just said splitter not thinking.

And an update from him this morning actually. He said he was playing with the vertical hold last night and the screen just scrolls left and right now.

He has several consoles he is hooking up the BVM and is using the switch to change to different consoles.

Some pics of how it is hooked up.

http://postimg.org/gallery/236vbttro/

[crazydean]

Not getting anything with that link. It just takes me to postimg.org

I'm wondering if the cable is too long. Analog signals don't do well on long trips. It could also be a poor quality switch.

[Fidde_se]

The sync is known to be low in PCE.

And every connector you add into the equation lowers it a bit.
Connector Attenuation....
https://en.wikipedia.org/wiki/Insertion_loss

Yeah you probably need the Sync amp, either build one form scratch.
Lower right: http://www.gamesx.com/grafx/pce_rgb.jpg

Or you could probably use the unused channel on the circuit you already were into,
some good ol' mod needed there.

[SignOfZeta]

Or just not use a SCART switcher. Most of them are super bad.

[thesteve]

is he using composite video as sync or just sync?
the SCART standard is composite video, but some mod the system to just do sync

[ClodBuster]

Or just not use a SCART switcher. Most of them are super bad.

So true. I've tried both cheap as well as expensive ones. They all introduce visible interference, some more obvious than other.

[L-Digital]

It's Almost certainly the switch. I have tried them all and most are junk. Post a pic of the switch please

The best switches you can fairly easily get are bandridge. There is also a good Hama out there but also some poor models so be careful

[MNKyDeth]

The scart switch he is using looks exactly like this one from this thread.
http://www.pcenginefx.com/forums/index.php?topic=20679.msg450985#msg450985

Correct link to pictures of how it is hooked up.
http://postimg.org/gallery/236vbttro/

I have the console getting sync from the composite video. I did not hook directly to pin 44 on the Hu6260.
The Euro scart cable I supplied him was from retrogamingcables.uk
He is using a scart to BNC cable from the switch. He says the console displays just fine using the original composite video cable and the RGB Euro Scart cable I supplied to him. The issue is only when he adds in the switch.

[L-Digital]

It's almost certainly the switch. If he goes direct from PCE to bnc adaptor without the switch does the problem persist?

There is only 1 good version of that type of switch and it is Hama

I have owned and tested it to be rock solid with PCE and other weak sync types

It has white writing that says Hama and is made of plastic, not metal. They do a cheaper version of the same switch with a lower profile and no white writing which is junk

[ClodBuster]

So I guess this switch happens to be the one you're speaking of?

https://de.hama.com/00042945/hama-scart-umschaltpult-3-fach-schwarz

I also saw another one with a slightly different case design:
http://www.expert-technomarkt.de/Empfaenger-und-Verstaerker/Hama-Scart-Switching-Console-100S-Schwarz-25-99,99.html?campaign=Commerce-Connector/Audio,Video-und-TV/HiFi/Empfaenger-und-Verstaerker/Scart-Switching-Console-%22100S%22

If one of these is the good one you mentioned, I'll give it a try.

[L-Digital]

First link is the one I meant yes


The other link didn't work

[thesteve]

you could add an LM1881 to the scart to BNC cable
it will give you a strong sync from composite

[MNKyDeth]

Ok, looks like he is going to try getting his hands on one of the Hama scart switchers. If that doesn't work then I will see about adding in a LM1881 to the cable.

I guess I should also mention that he has the exact same issue with his RGB modded Intellivision with this switch. He didn't tell me this right away so I assumed it could have possibly been the sync signal in the Duo. Now I know it's the scart switch as it fails with any of his consoles.