I'm currently gathering parts for the creation of a component YPrPb -> RGBHV (That's VGA, essentially) transcoder, using the chip mentioned here.
At the moment, I've got the schematic drawn up, and I've recieved the LMH1251 itself, along with the LMH6739 high-speed Op-Amp. Damn things are those little surface-mount jobbies, so it'll be a tricky job aligning and soldering them. I've heard about using a solder paste and an IR oven (essentially an element grill, like in a toaster oven) toalmost effortlessly solder surface-mounts, so I'll have a look into that. Once the rest of the parts arrive, I can breadboard it to make sure it works, then knock out a PCB and etch it.

Just for a rough idea of size, here's the pair of LMH1251 chips on top of a tape measure:


I was initially thinking of offering these to any Lumenlab members who wanted them, but the cost of all the components mounts up to about £50 (almost $100), and I'm not even sure if it'll get decent results yet, so don't hold your breath. I don't want to chage people exorbitant amounts for a sub-standard device.
::EDIT::
Here's the schematic

at least its not BGA

good luck

Looking forward to it. Good luck
Will it have VGA passthrough (I think it was one of the chip's features, not sure though), or only transcode from YPbPr to RGBHV?

I thought about adding the RGBHV inputs, but it would overly complicate the board, and I could just as easily use a VGA switch instead.

UPS seems to have lost my shipment. I'll hopefully be getting a calll on monday to find out what's happened. Even ParcelFarce would be better than this (though only because I'm not shipping anything fragile).

I will also build this transcoder. I will start in 1 or 2 weeks. I was thinking of using the "dead bug" technique for the first prototype. It consist of gluing the chips on their backs ("dead bug") on a copper board used for ground. Then, each part is soldered directly to the chips' pins.

I think it would be better than doing it on a breadboard because of the high frequencies in question. Breadboards are not very good at higher frequencies.

If the prototype gives good results, I may try the home PCB technique. If you want to share it, maybe you could post the PCB layout when you're done.

I'm going to alternately bend the pins up and down and solder some very short jumper leads to the chips, then cnnect the components directly into the adjacent holes in the breadboard. I'd ratehr make sure the design works before doing anything permnant (even if the circuit itself gives a low quality output, I'll know it's working and I can finalise the PCB design).

In other news, I should have the rest of the components by tomorrow. But I may be delayed in construction for a week or two due to moving house. Here's what my room currently looks like:

Plus all my soldering kit is in a box outside somewhere.

Nice. Mine's much worse (Not kidding!).

Oh fie. Seems the logic inverter I ordered was out of stock, so it's coming in a later shipment. Delays, delays...

Any news EdZ? It's been a long time without any info on the progress.

It has been a long time, but no progress has been made (on the transcoder from that is. There is new flooring in two rooms, and the kitchen is repainted and retiled. Belt sanders are evil fickle machines).

The final chip should arrive sometime this month, and I can begin putting it all together. Depending on how many boards i have to go through until I get a final working design, I may be able to distribute a few to anyone who wants them 9though don't hold your breath). Either way, I'll make the final board mask and circuit diagram available here so you can make your own boards.

Hello EdZ. I thought you'd never complete this project . Good to know you're still alive .
Mind if I ask a couple of questions?
Do you have the *.sch file for the schematic you posted?
How long did you wait for the samples from national to arrive?

Cheers.

I've taken up the reigns on this project, sorry to be dredging from such an old post, but soon I'll be testing the schematics he posted oh so long ago.

I've attached the current revision of my schematic, note that what looks like 3 separate amps is actually a chip, the LMH6734, specifically.

I dont really can't picture what goes where on that AgentWilsonx's circuit, that LMH6734. Can someone draw similar type picture like edZ's, that the circuit diagram has the chip?

It looks like it needs less components.