Making an RGB amp

[gtsamour]

Yes but this way (assuming you'll use regular components) you'll have half width but double hight. I dont see any gain compared to mine. I would suggest against it, the console's case wont close.

[Charlie]

If you want to make a test board that way, it will probably be good enough to let you determine if it is worth making the production board.  (You will find out real fast how critical component layout is when you are working with video signals!)  

If you use SMT components, the tallest parts will be the tantalums; with them on both sides, you're total board thickness will approach .250".  Will a 1"x1"x.25" pcb fit into your available space?  You can get shorter caps, but they qualify as a "speciality" item, and can cost up to $1.00 more each.  

Without knowing the actual space you have available (or it's specific shape), I guess you won't know unit you try it.

Hint: cut a few pieces of standard corregated cardboard box (usually .05" to .10" thick) to the proper shape to drop into your console in the selected area, then stack them up until something hits.  That will give you a close approximation to the allowable PCB length, width and height

Charlie

[soop]

both of you are invaluable.  Hopefully I'll get everything together by tomorrow, but your advice is golden.

[soop]

Ok, I have an update for whover's interested.

I'd probably do it this way again, but I laid them all out on the board, taped over them, and then turned it over to solder, removing legs as I went.
I got it onto a tiny space, about 5x5cm or so.

Then I found out caps have polarity and I couldn't figure out the direction without the legs   Put it to the side for a while after that.  Then I found another way, the stripe on the side, and was

I used solder to make the connections underneath (very tricky for me, it ended up being a bit messy, and I probably used way too much) and some jumper for the ground connections, which go to the outside, with the 5v running through the middle.

Then I wired it up to the expansion port using some coloured wire.

Then I soldered together a scart cable (also very fiddly on the din end, ended up melting through the plastic when a pin got too hot)  after that, I was nearly done.  Everything was wired up, I'd been soldering for several hours straight... and...

Nothing.

Took the multimeter to it, which was more difficult than necessary given the shortness I'd cut the wires to, and I couldn't get a reading from the live (using the ground on the circuit) so it's probably my crappy soldering which has cause the issue.

The next one I make, where I need an "L" connection, or even the 5v all the way through, I might just save a leg ot two and use them as the conduit. And the jumpering for the gound is messy and adds height, I think I'll loop the wires over rather than keep them under.

And the size is fine for fitting in a white PCE thanks to the size difference from the RF to the mini din.

[gtsamour]

If there's no photo it didn't happen

[soop]

As you wish... It's been dremelled obviously:

[gtsamour]

Looks gooood. Did you try to see if it fits into a Core?

[pnauts]

Hello to all, few time ago, I wished make a RGB mod from the elektor schematic (I suppose many of you know about it), I have almost finish all, the only remaining issue is the use of the sync only signal who generating some trouble, but it performs well with Composite using as sync.




wiring done

RGBS from my scratched lovely Duo.


The purpose was to use it on my Projector in my dedicated HT room but my projector works with H and V sync separated, so I'll have to use sync separator but I'm confident it will works.
The schematic was originally intended to be used on scart connector (and in this case the sync is done by the composite used as sync in RGB mode).
I'm pretty happy with results, the mainly complaint was for me the artefact scrolling issue, well noticeable on 1st stage in Momotaro Katsugeki, the green moutains with pines showing brighter vertical bars, or the 1st dungeon in Ys.
Happily, the mod solved this and provide more vivid colors and an image accurate.

[thesteve]

Your projector will likely work with 5v c-sync


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[pnauts]

no, it can use Csync on its horizontal deflection (from 1Vpp to 5Vpp on 2K2 load according to specs and schematic of the projector, Yamaha DPX-1000), but vertical also needs its own.
I know because I did try by using composite only on HD input and the sync output from my board (H & V) on V input of the projector, I had only little distorsion (probably from the unwanted Horizontal pulse).
I have good hope when I'll have both sync individually to make it works perfectly.
the sync output looks like below for the moment.



on TV with sync by composite (50 ohms load) it works very nice, but with the sync only (2Vpp) I have like a cropping with a little image missing. I'll have to fix it.

[thesteve]

The issue is the huc6260 only puts out 0.3vpp sync

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[pnauts]

on amp output I had 2vpp and with the sync separator I use now I have my Sync 5vpp.
I have to fix a problem that I encounter sometime on blue I have red flashes and on Red I have blue flashes and no flashes on green.
I'll provide a real Hsync instead of Csync 5vpp to see if it will fix it.

[pnauts]

Here are some pics of the CVBS and the Vsync with 681K Rset on LM1881



According to datasheet, it looks like the Vsync is too long (3H normally -width).
I change Rset and here my results.



live test tonight.
if it fail I wish to use a perfect Vsync instead of CVBS like.

A suivre...

[pnauts]

some many test performed.
I did try some various Rset with LM1881 with there -width sync signal:
182µs
204µs
226µs
234µs
242µs
264µs
272µs
300µs

I just wanted to check what that affect on image, all timing was ko on image.
My projector have also these inputs RGBHV compatible with the component, so I did try what some member did specify, put composite in the Y input and I have the same kind of trouble (some horizontal jitter about 2 pixels).
is the video output from PC engine is 480i with "black line" to fullfill the true resolution of the console (around 240).
I think I couldn't make it works because my projector do not accept such a resolution.
when I'm look at the Csync output by the Huc6260 the timing are a little bit strange when changing from horizontal to vertical (period changing from 64µs to 68µs). Anyway I used a LM1883 and I can see there is a missing pulse on the true Hsync output (I'll post a image).
when I use the software mode (RGB PC) I have no image jitter nor flash color but the image is zoomed.
I think I would have to use S-video as improvment on composite instead of RGB.

[thesteve]

Wow, good eye on the missing pulse
You saw it right
The 240P is the same field sent every scan 30fps

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