CurtPalme.com Home Theater Forum

[barco_75]

I'm interested in installing some graphics 808s Sony tubes into my graphics 808 to improve picture quality and increase bandwidth from 75 MHZ to 120 MHZ. I already know about the panasonic P16's, but I'm specifically interested in the sony tubes.

What additional components would I need?

I've read CRT Sockets/RGB Amps (1 pc 808s assembly), possibly the mounting bracket. What else? Any adjustments required in the switch? I'm not trying to make my graphics 808 an graphics 808s, just switch the tubes, however, if you have any part recommendations to improve picture quality let me know. I've already installed HD-145's and running my Sony Blu-Ray directly to a HDFury 1 and Gamma X to port 3.

[Curt Palme]

That's basically it, the tube mounting frames, the CRT sockets and the tubes. I should have everything you need.

[Curt Palme]

That's basically it, the tube mounting frames, the CRT sockets and the tubes. I should have everything you need.

[barco_75]

Is the mounting frame needed the piece that the lens and tube mount to or is it the metal frame that holds the glycol to the tube? Any adjustments needed (turn pots, etc) to compensate for the switch? I recall the tubes are more power hungry.

[Curt Palme]

Oh wait, yes, there's a filament mod that you need to do. The 7621705 has a couple of current limiting resistors in the filament supply line, but short those out, and that will bring the filament back up to 6.3 volts that the tubes need. Otherwise the tubes will sit at 5.5 volts, and the pix will be a bit dim.

The mounting frames that hold the tube and lens in place is what you need.

Other than G2 adjustments, that should be it.

[Curt Palme]

Oh wait, yes, there's a filament mod that you need to do. The 7621705 has a couple of current limiting resistors in the filament supply line, but short those out, and that will bring the filament back up to 6.3 volts that the tubes need. Otherwise the tubes will sit at 5.5 volts, and the pix will be a bit dim.

The mounting frames that hold the tube and lens in place is what you need.

Other than G2 adjustments, that should be it.

[barco_75]

Thanks Curt, I just got mine running last night with the stock 808 graphics tubes. When I posted this message, I was noticing a lack of sharpness in the stock tubes at the corners when displaying a tight cross hatched calibration screen. However, I played a movie and damn the stock tubes are awesome. I don't notice the lack of sharpness even though it is there. Is the lack of sharpness at corners normal on the 808 and most projectors? I'm going to run the configuration now as-is and see if I get the bug to tweek. I've heard the sony and P16 are better, but I'm not certain how "much" better it might be.

[ecrabb]

Oh, you're mostly worried about focus in the corners? That's the lenses. The HD-8's corner focus (or lack thereof) and overall softer focus was the secondary reason for guys upgrading to HD-144/145 lenses, the primary reason being color filtering in some HD-144/145 sets.

If you want better corner focus, you'll probably want to shop for a set of HD-144/145's, which should be getting a bet easier as more sets seem to be getting parted out these days. You'll also need to buy or build a set of adapter plates.

That, or just tolerate the software corners since you don't generally look at the corners, anyway.

SC

[barco_75]

I have the hd-145s and adapters. Just wondering what's the normal expectations with those lens.

[barco_75]

I adjusted the focus yolks and digital controls. I adjusted yolks for best center focus and then used digital controls for perimeter. I think I ran out of adjustment on the top with the electronic controls. Could not get corners, sides, or top and bottom as good as center. Corners was fuzzy. Hd145 big improvement over hd8s. Guessing the fuzziness is limitation of all lens unless you shrink your raster which doesn't seem like a good idea. I did max the raster very close to edge of phosphor, maybe 5 to 10 mm from edge.

[ecrabb]

Damn, sorry - missed that you already had 145's on. Yes, if you're running the corners of the image close to the edges, the corners will be softer. It's a trade-off.

How hard did you work at Scheimpflug?

SC

[barco_75]

I think I did a good job on the scheminglug. I get even fuzzyness on all corners but not top centrer. I adjusted projector tilt at max angle per barco lens to get it close to ceiling ( I have high ceilings). Guessing that's causing the fuzzyness at top. Maybe the schemiflug not quite right since its more fuzzy at top. At the end of the adjustments I shifted raster down ( up on tubes toward top) to get image lower. I know you are supposed to keep it centered but I don't see any harm in doing that other than the burn in issue which is not an issue to me. It also helps get the image away from fuzzy top. A reason other than burn in to keep image centered vertically?

[barco_75]

Just thought of this, the fuzzyness at top could be do to my projection surface. It's a wall (drywall) and it may not be plumb or flat. I got the projector as square as possible. A screen would help I'm sure but I don't want to turn to see a screen on the wall and the high ceiling would require a custom screen with the drop needed to conceal it.

[barco_75]

Curt, in lieu of of modifying the R761705 SMPS could you just drop in the R761706 or R7690205 that was designed for the 808S?

[barco_75]

Bump

[Curt Palme]

Yes, that will work fine.

[Curt Palme]

Yes, that will work fine.

[km987654]