CurtPalme.com Home Theater Forum

[gjaky]

Okay, my brain won't stop when it is about tuning up my PG xtra.
I have an XG tubeset with lenses and LC hardware in sight, and I am thinking about modifying my PG chassis to accept the XG LC tube hardware. To my understanding the PG xtra tube shell is very-very similar (if not the same) to XG AC's tube shell, and given the fact there was AC and LC type of XG they should have some similarities as well. I didn't find any valuable information about XG AC->LC conversion not to mention PG xtra AC -> LC. Can Someone light me up in XG AC-> LC conversion, or can tell about the XG AC - PG X tube shells' differences?

[CasetheCorvetteman]

As far as i know the tubes all have the same face on them. They are all P16s.

[gjaky]

But the two big black screw have the same base width on both type? Probably I'll have to change the red and blue tube, because not sure if the longer XG tubes will fit in my. PG

[CasetheCorvetteman]

The LC housings wont mount up to the AC mounts though either as far as i know, when i looked inside the LC XG the mount is different. Im not sure by how much or if they will bolt straight into an AC XG, i havent looked close enough to know for sure.

[digitalayon]

This would be a non-starter for me.....I'm all for modding but this goes beyond!!! But if you like a challenge....mod away!!!

[CasetheCorvetteman]

You give up very easily then by the sound of that.

[gjaky]

Well I thought I could do it with some drilling and a bit machine work. But now it seems to be a bit more difficult.
So here are pictures what I gathered:

This is my PG xtra's face shot, note the small gaps between the tubes:


This an XG AC, found on e-bay, note the wide gaps between the tubes:


This is SpankyHam's XG LC, note the smaller gap between the tubes than XG AC:


Also if I am right the XG LC tube assembly is 177mm wide while my PG tube assembly is only 173mm wide, but the maximal inner width of the PG xtra chassis is 53cm so I am afraid they won't fit easily in.

[CasetheCorvetteman]

I had a feeling the chambers were wider, itll take abit of cutting, but you may still get them in between the plastic sides, if you cut out the right areas and modify the mounting points youll be right, id move the tubes further forward in the set, maybe leave the green back further. This will mean a slight difference in tube face usage, but green will be larger which is ok cause it would mean itll wear more in sync with the blue.

Big job, but certainly not imposible for a man of you abilities.

[digitalayon]

I just think it would be easier to re-tube the XG.

[gjaky]

Well, maybe but, nowhere near a burnt tubed XG. Anyway an XG is bigger and louder than a PG, and my PG just fits right in it's place on the floor, don't want any bigger pj at the moment. Also I think the PG xtras are far underrated, so I want to show everyone what can be done with these sets.

[digitalayon]

I am listening....I have a 933 runco....same as an extra....you have my attention. What is your plan? I would not mess with the AC stuff. I would leave that alone. What I would be doing is finding ways to increase bandwidth and moome type additions or modded cards for adding hdmi or dvi. I think that would be more usefull.
.

[gjaky]

To be honest the bandwidth of the PG xtra is not bad at all, however I think I've found a way to increase the bandwidth of the machine, it is described here:
https://www.curtpalme.com/forum_archived/viewtopic.php@t=32262.html
The above mentioned CXA1209P is clearly the bottleneck regarding bandwidth, it should be replaced with the CXA1299P (if I could find one! ) or bypassed with an other part, there are countless similar RGB predrivers in the 150-180MHz range usually found in 17"-21" CRT monitors, but none of those are pin to pin compatible with the CXA, so massive rewiring would be neccesary but that is not a wise idea when we dealing with high frequency.

On the other hand I think the best thing which has ever been invented for CRT projection is the liquid coupling, it really makes difference.

[CasetheCorvetteman]

Adding DVI or HDMI is pointless on a PG, its factory fitted with RGB-HV. Use an external HDMI - RGB device.

[gjaky]

[CasetheCorvetteman]

Yeah either device will do.

Digitalayon, did you not recently say you believe HD-145 lenses are a simular answer to LC, questioned the advantage to going with LC and claimed there to be misinformed guidance within the thread? Im just trying to understand this here cause you appear to have a differing stance in each thread. Maybe im reading itvwrong and youre trying to steer Gjaky away from the major step up to LC?

[gjaky]

[digitalayon]

[gjaky]

While HD-145 is really great lens when it comes to resolution, but any LC lens beat is when it comes to contrast, personyally I appreciate more the contrast ratio than the pure resolution. Not to mention HD-18, and HD-134 lenses are just as good as HD-145

I don't have an NEC XG I only have access for three tubes in XG LC mount with lenses, and no, I haven't purchased them yet, just thinking on it... maybe it would worth the effort.
Anyway 8" LC barco also can be done with original barco LC chambers... my friend has one spare set 8" LC chamber with scheimpflug adjustments.

[digitalayon]

OK now you are making sense......I did not know you were not getting the whole projector. And the Barco tanks probably came from a Cine8 or Onyx model since they do fit the 1208. Good call on the contrast ratio over the resolution though. But perhaps you will find a way to have your cake and eat it too.

[Nashou66]

LC's also tend to be sharper as well.

Nashou