Is there a way to get composite out of coax?

bacteria · Post by **bacteria** » Mon Sep 08, 2008 3:04 pm

Got a couple of unusual plug'n'plays recently. One just ended up with the usual mound of games I already had (no use) and another one which only has coax output and not composite to connect to a television. I can only use composite or RGB after all. I haven't had this issue before, normally composite is the standard for video.

Only spent Â£1 on it so it doesn't matter if I only use it for bits (has a nice controller as you see in the pic); and it also came with 4 x AA batteries, frankly I can't lose as the batteries are worth more than the Â£1 anyway!

So I can make this work on composite, easily; or shall I just use it for parts??

hailrazer · Post by **hailrazer** » Mon Sep 08, 2008 3:34 pm

What you're looking for is an rf demodulator.

I don't know how hard it would be to DIY one , but it might be an option ?

Dr. KillGood · Post by **Dr. KillGood** » Mon Sep 08, 2008 3:41 pm

Looks like the coax out has an extra board for it, so maybe it is RGB our but that extra board changes it to coax?

IDK.

bacteria · Post by **bacteria** » Mon Sep 08, 2008 4:35 pm

Just shows the cheap Chinese crap this unit is - the shielding plate underneath had the Sony Playstation card under it - cut out from something or other!!

Desoldered the RF modulator; just connects to three pins going into the board mobo.

...so, is this destined for spares (resistors, etc) or anyone got any ideas?

Super Cameraman · Post by **Super Cameraman** » Mon Sep 08, 2008 4:58 pm

Well, if it only connected by 3 points, maybe the three are video, audio, and ground? That's my guess, but I'm probably wrong as usual.

Mario · Post by **Mario** » Mon Sep 08, 2008 5:14 pm

Oh, please, this is way too easy.

Ever tried to portablize an NES? If you have, you'll know that the NES board outputs composite. The RF box takes the composite and turns it into, well, RF. Look at the second picture you posted. See the three pins labeled VCC, V and A? Simply hook your video and audio to V and A (and ground of course). If it does not work, try building this video amp. If it does not work then, then I don't know what to tell you.

But it should very well work, because it is highly improbable that the main board would only output RF.
But I do hope you get it working!

Super Cameraman · Post by **Super Cameraman** » Mon Sep 08, 2008 5:40 pm

I WAS right! Awesome!

bacteria · Post by **bacteria** » Mon Sep 08, 2008 5:47 pm

Excellent Mario and Super Camerman, I will give it a go over the next days - I agree, this seems logical. That's the thing with these plug'n'plays - they often throw up wobblers! I wondered if V(ideo), A(udio) and VCC (presumably data line for the RF?) but was surprised the system didn't offer a standard composite and audio plug as you normally get, rather than RF. No, haven't done a NES yet, will do on my Multi-Platform project though.

BTW - removed the GBA Transverter from my old project and got it wired up with a new GBA board, next week is project week (not this week, although I can snatch an hour or so here and there), so will get the GBA working on my Mini-Platform portable in the first half of next week, and also this plug'n'play system too (and others). Will post when done ("News" section, tagged onto my existing thread).

Talking of weird plug'n'plays, some use multiple grounds, for example d-pad uses one ground, A & B buttons another one. Sometimes you can link them and the system works, sometimes not - anyone know what to do in these circumstances? Don't want to have multiple grounds for buttons, as a single common ground is needed.

Mario · Post by **Mario** » Mon Sep 08, 2008 5:51 pm

bacteria wrote:I wondered if V(ideo), A(udio) and VCC (presumably data line for the RF?)

VCC means power in, the RF box needs some form of power to run.

As for your ground problem, I don't know what to do about that.

That's pretty strange (although it's also strange that there was a Sony card in there and that it had RF out

(or are you talking about other systems?)). So sorry, don't know what to do about that.

Dr. KillGood · Post by **Dr. KillGood** » Mon Sep 08, 2008 6:04 pm

Super Cameraman wrote:I WAS right! Awesome!

I WAS RIGHT FIRST!

DK · Post by DK » Tue Sep 09, 2008 3:52 am

Dr. KillGood wrote:
Super Cameraman wrote:I WAS right! Awesome!
I WAS RIGHT FIRST!

There's a difference between composite and RGB...

Rekarp · Post by **Rekarp** » Tue Sep 09, 2008 9:27 am

I have never seen a console output RGB to a RF modulator. Every single one outputs a composite like signal to the RF box. Ataris output a premixed audio/video signal and the NES has separate lines. Hopefully yours are separate.

Super Cameraman · Post by **Super Cameraman** » Tue Sep 09, 2008 1:31 pm

If anyone has any suggestions about the common ground problem, please share. Maybe it has something to do with relays or something?

bacteria · Post by **bacteria** » Tue Sep 09, 2008 2:44 pm

Ok, tried it; got a wavy red and green blodge line scrolling on the screen, so presumably that means the "V" was not for V(ideo) composite after all. The sound was rather crackly too. Could be the unit doesn't work after all, couldn't test it before as it was RF.

Spent too long on this plug'n'play; using it for bits now. The games on this one were quite basic anyway, just thought it would be nice to have a go.

Rigged my PS2 screen (widescreen) I got a while back into a GameCube supply (12v). Composite on the PS2 screen is not as good as on the PSone screen; intending to keep the screen for a future project with RGB - may well use the PS2 screen for a GameCube system as the screen is 12v and ideally the GC takes 12v to get all the various voltages it needs. Future project, too many others on the cards at the moment.

Mario · Post by **Mario** » Tue Sep 09, 2008 4:05 pm

bacteria wrote:Ok, tried it; got a wavy red and green blodge line scrolling on the screen, so presumably that means the "V" was not for V(ideo) composite after all.

Did you try the video amp?