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Discussion Starter · #1 ·
Hi,


My name is Joe Jasniewski. I'm a newbie to HT using CRT projection; I recently purchased an ECP 4100, after futzing around with numerous LCD panels and OHPs. I'm happy to read here that this unit has flexible optical adjustments and modifyable electronics. I've printed many a thread, and hope to start one of my own, to document my setup and modifications, so that others may find some specifics in just one place.


Just got it hung from the ceiling, about 6 ft up off the floor; cranked it up with a boat winch mounted to the stock ceiling mount pipe! (was hairy for a few minutes there...) I havent even gone through the mechanical convergence procedure yet; I do have the owners manual another technical manual printed out for this unit. I've only looked through the help key procedure...


So, some quick questions; opinions, answers muchly appreciated!


1. I'd like to do the grillework based fan mod, but the projector is up. I do notice clearances in the mounting bracket for the two screws that hold the side panels to the projector bottom. Can these panels be removed in situ?


2. I want to run my signaling (PC, Composite from VCR, S-VGA from DVD, Cable) through a Viewsonic VP box. Is it better to put the box up with the projector (Drive a short RGBHV) and run 4 lengths of signal cable, or is it better to just run one long RGBHV from the Viewsonic? Are there any specific mods to the Viewsonic that I can do which will help it drive 20 ft?


3. The projector has some sort of verticle sync trouble (image hops up and down erratically, even with the internally generated green text) which goes away after the projector has been run some. It came back when I disconnected power (and thereby killed any standby power) and went away again after running for a short time. Could this be a capacitor reforming? What specific component(s) should I replace to fix this? Believe me, it freaked me out when I got it, let it sit for a day, then turned it on for the first time. I thought I heard a "snap" sound when it stabilized the first time. No snap heard on the second eventual stabilization...


4. I have a sheet of the Plastex to use for a screen. My permanent location (cant get any closer because of a skylight) has the maximum image height a few inches over 4ft. How important is it really, to use all of the available tube phosphor? Is it OK to reduce the size to fit my 4' high screen, or should I buy another sheet to make it a 5' screen? Should I buy Ken H's Goo and just paint in a screen? I'm sorry I dont have the exact distance to the screen...


5. The Woman who's put up with all this (caring for screeching toddler while I'm running dedicated AC through the attic, got the projector hanging by ropes, etc) has asked me to drop the image about 1ft. Right now, I've got the tubes sighted pretty much square to the wall. Dropping it will keystone it some and I know I can correct for this, but doing so will be at the expense of the % total phosphor I have lit. What should I do in this case? Sacrifice myself ;') or some of the phosphor in the tubes of my 1K$ projector?


It's good to be able to join the club, thanks for having me!
 

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Discussion Starter · #2 ·
The plane of the three lenses is 89" to the wall, where I plan to mount the screen.


"Thanks for all the replies". I cant believe not one person has a thing to say about anything I asked. It's pretty discouraging! What, am I not worthy of any response because I havent spent a gazillion $ on just my scaler? Hey, you have to start somewhere...
 

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1. Fan mod is easy with the projector mounted. Simply remove the side panels which the fans are attached to and work on them in your workshop.


2. In theory video processor as close to the projector as possible is best, but my setup has it by my equipment rack and I run long RGBHV cables. Really a coin toss.


3. No help here, sorry.


4. Shame you've mounted the projector already. Physical placement of the projector sets the screen size (width). Height can be adjusted within reason for 4:3 or 16:9 screen sizes. The projector can tilt to put the image higher/lower on the wall (up to 15 degs).


I strongly advise against running your projector wider/less wide than the throw distance is set for. (ie: now that its mounted on the ceiling, your only option is to move the screen closer/further). Using the electronic controls to 'shrink' the image will pre-maturely wear your tubes.


5. Minimal keystone will help image stability, but a few degrees won't matter.


The main risk you have here is projector throw distance being wrong for your screen size (4). I would carefully review this.


Roo
 

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Well, that's not a great way to illicit any responses either, sometimes it takes more than 24 hours...but...


1) Yes.


2) Don't know about the viewsonic


3) I assume you have a source connected? If not, it wont stabilize. Other than than, could be any part. Start by eliminating "modules" then you can get down to specific parts. Since you haven't done any setup, there's no telling. There's only about 10000 specific parts in there covered in 100 pages of service manual so....to answer your specific question, it could be a cap, or a resistor, or a loose connection changing with warmup.


4) This will depend on the overall size of the screen, which determines thrown distance. throw distance is 1.5x the width of the screen. Then you adjust vertical size to fit. What ratio screen is it? You should know the distance to the screen prior to the mounting. Based on your second post, I would assume a screen width of 60" if doe properly. Painting it will have nothing to do with properly setting up the proper throw distance and geometry. But, as far as ScreenGoo, I've heard its awesome and am going to purchase some myself before too long.


5) Again, all a function of screen size. I wouldn't mount pj until I knew what screen was going with it. I don't see how you can. Certainly if you don't mind sacrificing brightness/longevity/stability you can electronically adjust for just about anything. You're the only one who can decide what is important to you. I think it would be just about unanimous that everyone here will tell you to use the pj to its full potential. That means doign everything right the 1st time.
 

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Discussion Starter · #5 ·
I guess the forum just dumps your reply if an attached picture is too big. I wrote an elaborate reply, but its gone. Here's why I'm stuck with the throw distance I have; I'll need a custom screen size is all; I understand.
 

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the light or the mounting location above? There are lots of ideas for mounting that could help move you back. That's the issue...my screen is 92", therefore my pj (same as yours) is 138" from the screen. If you can move back (and want a larger screen) then all is good. But again, mounting is a funciton of screen width, not heigth. If you determine your width, then height will be a function of aspect ratio.


For example, you are 89" from the wall. That means a 60" wide screen. If you want a 16:9, then it would be approx 34" high. If a 4:3, then 45" high. there are other ratios, but these are the most common.


As far as the forum dumping...sometimes I can hit the back button and everything is there...then I jsut edit the pix to be smaller.
 

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Discussion Starter · #7 ·
The light is actually a skylight and a rather large, deep, inpenetrable structure. But it sounds like I dont want to go closer, per se. I can easily live with a 60X45, 75" diagonal for the room I'm using. I wanted to use a smaller image initially, so I can run the brightness a bit down. I'll cut my plas-tex sheet to fit this size; I could even do a 1.5" black border.


While I understand "why" not to comp for the throw distance by reducing the image electronically, what's behind the taboo (As suggested by Andrew) of running "wider" than the throw distance is set for? Besides chopping off some of the image on both sides...) Are the tube faces optimized for a certain scan width - even though the phosphor deposit goes wider?


I'm considering a RGBHV cable, but the guy says the bandwidth is only 250Mhz and not suitable for quality video. What shound the cable bandwidth be? An engineer at work told me that the delay skew between the individual cables could be a problem; is this what's behind the lower bandwidth detrimental effect?


I'm pretty excited to get this project going and set up the projector mechanically. Like I said before, I will contribute my results.


I never found the type of fan used to replace the stock fans, as the post was so old it was no longer carried or something. If anyone has that number (NMB 3110KL-04W-B10?) it'd be appreciated.
 

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Joe, The bandwidth of the pj is 65MHz so a 250MHz bandwidth cable is more than enough. Extron boxes are typically 300 MHz but used to be 200Mhz. Here is a link for bandisth calculations:

http://www.autopatch.com/mhz.htm


figure out what you want to run and go from there. Modified, I use mine at 1280x720 @ 72Hz. RGB is by far the better signal to run to the pj. S video and composite (with the proper decoder card) are your only other options...so as you can see, not very good. You really don't have much of a choice with the ECP...there are some pjs that take a SDI in but I think it was custom made, and not for our (up to) 12 year old model.


As far as width...since throw distance is a function of width, if you stretch your pic too far you could run the picture into the ede of the CRT. this causes it to run hot and possibly damage the CRT. I keep my raster about 1/4" away from the edge of the tube on both sides. Normaly there is plenty of range top/bottom.


there is a repalcement NMB although I am not sure of the number. Do a search for Andrew Low and fan mods...he had the nubmer posted after some communication with the fan manufacturer.
 

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Quote:
Originally posted by jjasniew
While I understand "why" not to comp for the throw distance by reducing the image electronically, what's behind the taboo (As suggested by Andrew) of running "wider" than the throw distance is set for? Besides chopping off some of the image on both sides...) Are the tube faces optimized for a certain scan width - even though the phosphor deposit goes wider?
If you overscan your tubes, you can cause them to overheat -- causing them to (physically) break. The distances set in the manuals are slightly conservative, but not by a lot. You can go a few percent wider, but most people keep it around 3% to 5%. Using the 'most' phosphor you can is good -- but it isn't something you should do unless you completely understand what is going on.


And for anyone reading that doesn't understand why you don't want to go the other way -- using a lot less of the tube face will cause it to overheat, prematurely wearing the tube.

Quote:


I never found the type of fan used to replace the stock fans, as the post was so old it was no longer carried or something. If anyone has that number (NMB 3110KL-04W-B10?) it'd be appreciated.
If you contact NMB you'll find that they have renamed the part, but still make the same fan. As it turns out, the PC Power and Cooling "silencer" fan was an exact match for my fans (both CFM and static pressure). The number you give looks pretty darn similar from memory to mine, so you should be ok -- but you might want to check the CFM/static pressure.


My ECP has been running with the replaced fans & grills cut for well over a year now. No problems.


My recommendations on fan modifications:


1) Measure the internal temperature using a indoor/outdoor themometer, I picked up a cheap one for $20. Measure your temperature over a few movies.

2) Now remove the side panels, and cut the grills out. Clean the existing fans (dust them) and remount. Re-measure your temperature, still good?

3) Check the specs on the stock fans CFM and static pressure. Either replace them with equivalent NMB fans, or choose a 'quieter' fan but remember to match the specs.

4) Install replacement fans, re-measure temperatures.


Enjoy. Feel free to stop at any point along the list above. Many people find removing the grills is plenty.


After 4 steps, my fans are darn quiet. Its not a Dwin, and probably a little louder than Tim Martin's fan mod for the Marquee, but not much.


Roo
 
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