CurtPalme.com Home Theater Forum

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

This is just meant to be a place to put info regarding the various kinds of tubes our projectors use, their characteristics, and compatibility between them.

To start,
9" Panasonic types:
P19LCP type, standard resolution, blue/white gun bedding strips, no G3 grid
P19LPB type, medium resolution, white/white gun bedding strips, no G3 grid
P19LQF type, high resolution, brown/white gun bedding strips, has G3 grid
P19UG type, high resolution, brown/white gun bedding strips, has G3 grid

I just put LUGS into my G90 which was equipped with LQF types, which I found to be interesting
because I had always been under the belief that G90s are equipped with LPBs?

Electronic focus will have to be redone in the G90. The LUGs do focus differently as compared to the LQFs.

Please feel free to add your own information to this for any CRT not yet mentioned.

Include any information you have concerning tube substitutions and so on.

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

Chris, what are the basic parameters when it comes to tubes working in certain PJ's?

1) Heater voltage.
2) HV.
3) Tube physical dimensions.
4)?
5)?
6)...

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Heater voltage is always going to be 6.3 volts AC.

I don't intend for this to be a detailed technical compilation of every parameter of every tube, just information that is useful
to us if we need or want to substitute tubes.

It's generally going to be about knowing the difference between, for example, the four 9" types I listed in the first post,
and how they are different and how they might or might not be compatible with a projector that currently has one type,
but you are considering using a different type.

For example, we know that the LQF and LUG types have what appears to be the same electron gun assembly, at least upon
visual inspection. I know that they are interchangeable in a G90 because I just did it. I'm running an original red LQF and
the blue and green are LUGs. Bias and gain have to be adjusted, but the tubes are much fresher than the red, so that is
to be expected even if their design operating voltages are the same.

So what IS the difference between the LQF and the LUG? It's nothing I've actually seen yet. And there is much to be done
before I can find out how sharp they'll really get.

I do know, from trying it, that there is apparently no magnetic and focusing issue associated with swapping out an LPB for a LUG in a G90. Either type focuses fine and in the same adjustment range. So I have confirmed for myself that the LQF and LUG are essentially interchangeable in a G90 except that if there is a difference in ultimate sharpness, I haven't reached that point of discovery yet.

The G90 was allegedly normally shipped with LPB tubes. But LPBs lack that third grid and the bedding strips are white/white.
Physically the guns look like LCP guns but LCP guns are known to be lower resolution and have blue and white bedding strips.

I have not yet seen or tried LPBs or LCPs in a G90 but I don't expect them to be sharper.

Before long I expect to test out the LPBs and LQFs in a Marquee as well. I want to find out if there are any significant compatibility
issues between similar tubes that might fit and work in various projectors.

I would hope that others contribute their own findings regarding tube substitutions as well.

thewolfman · Joined: 28 Mar 2011 Posts: 1311 Location: Sweden

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

I would not expect it to be an improvement. I don't think there'd be any issue at all in making it work, but you could get the same effect by just defocusing a little bit.

But then again, if the supply of LUGs were to run dry and only LCPs were available, it'd be good to know that you could still run your G90 with LCPs.

Really, LCPs are not terrible. They'll resolve full 1080P. I'd never put any effort into LUG tubes, though, if my aspirations for image sharpness ended at 1080P. They don't.

I would hope that those who know definitively would contribute to the following list:

Sony G90, stock tube types you have definitely seen are.......LPBs, LQFs, LUGs? Which (possibly more than one) are definitively provided in a stock G90? The answer MIGHT be all three.

Barco 909/Cine 9, have you ever seen tubes other than LUGs installed in them from the factory?

We know about Marquee 9500LCs. LCP is standard, LUG for high resolution simulation applications. I've never heard of LQFs or LPBs being run in them. But I may try it.

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Tonight I test ran a red P19LPB in a Marquee chassis. It has the same pinout as a LUG, G2 on pin 6, and it worked fine in the Marquee. No abnormalities were noted. Though not completely run through its paces, as it wasn't even potted into an LC assembly and cooled, it seemed to work just fine.

Next up, I'll try an LQF in a Marquee.

thewolfman · Joined: 28 Mar 2011 Posts: 1311 Location: Sweden

What would a set of LQF potted in a Marquee housing cost me? If they are confirmed to work well with LCP VNBs. Just making small talk really. Keep it up!

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

I don't have any new condition LQFs. Just two rather well used ones.

You provide the tubes, I provide the LC hardware and the labor for 50 bucks each and you pay shipping. Clear C element included.

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

I checked out a second LPB and this time did more testing on it. It even seems to focus normally.

At this time I declare that an LPB will run in a Marquee with no issues. But the LPB has G2 on pin 6, like a LUG, and not on pin 2,
like a standard LCP.