A recent thread of mine ("First impressions with LC tubes, and a potentially interesting theoretical question." http://www.avsforum.com/avs-vb/showthread.php?t=567976 ) split down two equally interesting (to me, at least) paths. The original thread concentrated on potential benefits and means of cooling the glycol in LC tubes.
The parallel path (to whit this thread is dedicated) speculated that 07MPA tubes (LC versions of the common 07MP) could provide a relatively easy LC mod for several common PJs (among them, my BG801 PJs.)
I'll start this thread with appropriate quote pastes (librally trimmed for space, where there was overlap between topics: )
(original posting by me: )
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
(I assume TheFerret was talking about the LC/Lens mod, not the LC/glycol cooling mod.)
Quote:
Quote:
Quote:
I think that summs it up. I'm actually quite a bit more interested in this topic than the other . . . "First impressions" was for theory... while this thread has some practical implecations for my primary HT.
Practical enough, for example, to inspire me to put my picturetel tubes in my happily working RD801 and put the good MPA tubes in my BG801 (were I to find lenses.)
The parallel path (to whit this thread is dedicated) speculated that 07MPA tubes (LC versions of the common 07MP) could provide a relatively easy LC mod for several common PJs (among them, my BG801 PJs.)
I'll start this thread with appropriate quote pastes (librally trimmed for space, where there was overlap between topics: )
(original posting by me: )
Quote:
| Originally Posted by jtnfoley Touched upon recently was the need for LC chambers to be full, even for very short periods, to prevent phosphor wear/burn. In that thread, it was very briefly speculated that keeping the glycol cooler might _extend_ tube life. Given how easy it'd be to mod an LC tube for greater heat transfer, I think it bears discussion. I've laid my hands upon my first sets of LC tubes (from my recently acquired RetroData 801 PJs) and the first thought I had was "convection cooling" when I saw the loop of hose running around the tube bell. Besides providing a short circuit path for HV, what's to prevent us from changing a length of the tubing to copper of black tin? Just as importantly, what quantative test can be applied to whether tube life is improved? (IIRC, black tin won't oxidize and pollute the fluid, which is why it's used in beverage systems. Fifteen year old memories here, probably flawed.) [RANDOM, IGNORANT SPECULATION] I'm thinking of CMJ's frankenyolks, which may cause greater wear given a spot size markedly smaller than the original when the phosphor was laid down.[/RANDOM, IGNORANT SPECULATION] |
Quote:
| Originally Posted by 4101 CRT Here is another thought with your 07MPA tubes. The front chamber will allow HD-145 or HD-144 lenses to be fitted directly to it. Everyone wants color Filtered lenses on there PJ you can do it without adaptors with the 07MPA. The only question is what the focus range will be with the LC housing designed for short projection and HD-144 lenses made for long throws? I have a set but haven’t tried it yet, just think color corrected and filtered plus liquid coupled lenses on a 801, all the 808 users would be jealous of you. Pat |
| Originally Posted by jtnfoley Hmmm put the LCs in my BG801 FP . . . that's a mod I had considred but decided I could not do it with GT114 and GT117 lenses. I'll have to try it with my burned MPAs and 42000 hour BG801 chassis (if I can find lenses.) Good point on the air bubbles, that reason did not even dawn on me. |
| Originally Posted by Mark_A_W You can't add AC lenses to LC tubes, there'd be 2 C-elements for a start...it won't focus. |
| Originally Posted by Ile Have anybody ever tested Retro LC-chamber+C-element with HD8* or HD144*/HD145* lenses? *Certainly original "C-elements" have to remove from lenses... I'm going to test it some day, unless somebody can tell it doesn't works.  |
| Originally Posted by TheFerret SO, who has done this yet? |
Quote:
| Originally Posted by jtnfoley If I can lay my hands on one or three lenses I can do this with my collection of spares. Being an ignorant noob, however, prevents me from doing an accurate analysis. Chip, got any HD144 or 145 lenses in your collestion? |
| Originally Posted by 4101 CRT For a cheaper test you can also just use the normal lens from any ECP projector is HD-06? darn I forget the number, anyways you don’t need to use HD-145 color filtered just for the focus test, you can find many of the other lenses on Ebay for cheep. As Mark-A said you may need to remove the first element on the lens or two c-elements will be combined and not work at all. Last for Techman707 the 07MPA or 07MSPA tube is actually just a 07MP with a different housing. It has a LC element and tubes that wrap around the neck filled with glycol. The 07MPA’s also have bolts that fit the smaller lenses found in ECP’s this is what got me thinking about adding color filtered HD-145 to the tubes, 07MPA’s are found in retro’s. |
| Originally Posted by mrking Hmm I wonder if any of you freaks could use my sets of HD214 lenses for this experiment? They are for Retro 801s and 808s and 708s. I happen have a whole bunch of these. Maybe 10 sets or so. According to Per Johnny these should be able to focus at an image width of 260cm but a friend of mine who tested these doesn't agree. Since these doesn't have the corner focus adjustment they are rather blurry in the edges. But if someone were to test and butcher on of these and combine them with a set that has corner focus then maybe they can be made to work? The 07MPA and 07MSPA can be found int Barco Retro Graphics 800 and 801s and also those ugly Sony TV cubes Sony RVP401 is one model I believe. |
I think that summs it up. I'm actually quite a bit more interested in this topic than the other . . . "First impressions" was for theory... while this thread has some practical implecations for my primary HT.
Practical enough, for example, to inspire me to put my picturetel tubes in my happily working RD801 and put the good MPA tubes in my BG801 (were I to find lenses.)
