CurtPalme.com Home Theater Forum

[barco_75]

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So my 808 hybrid is ceiling mounted. My plan is to change my MEC tubes with fresh Sony tubes with the better amps.

Just removed the MEC tubes. Changed the mounting brackets for the Sony's. Ignored the instructions below which I really hope wasn't necessary. Low and behold, I can't fit the Sony tubes with the chassis mounted to the ceiling. The CRT neck is much longer than the MEC. Looks like Barco intends for you to take the entire projector down then turn it upside down to install the tubes. Tell me it isn't true!!

Is there a trick to this? Only thing I can think of is to make a bracket to lower the crossbar that all the mounts are installed on. Then put the tubes and brackets through the front as directed. Shim it up and then rely on the long metal rods to hold it together. Seems like a total pain in my rear. And I don't even like the idea that much. Any suggestions on how to do this and do it safely?

[Decibel]

Try to remove some boards, then insert the tube's sockets (tubes without the amps obviously) into the holes of the frame.

[Curt Palme]

Umm yeah, I've replaced lots of tubes in 808s, and there's no way I'd do it on the ceiling. Grab a friend, wield some muscle!

[Curt Palme]

Umm yeah, I've replaced lots of tubes in 808s, and there's no way I'd do it on the ceiling. Grab a friend, wield some muscle!

[Ile]

I have done it in ceiling. Mount tubes to black supports at table and then secure tube assembly by those two long rods one by one. You need friend to keep tube at correct place when installing those rods. He need also support tube when you install next one, because you need to remove other rod at that point.

When all tubes are hanging by four rod-bolts, it's time to assemble top bridge plate.

It can be done even by self if you trust that one rod would keep tubes weight when you install next one.
My friend leaved green tube hanging by one rod when we chanced blue tube to his 808s. I was bit worried, but it didn't drop.

If your friend is strong you can install all three tubes+lenses at one time to top bridge plate and then install full packet to projector.

[Decibel]

Curt spoken well.
When you unscrew the long side pins, the tube's frame will be free, so there is a real risk that falls all the tube's assembly.
So if you must to remove each tube's frame you will be forced to do it with the projector on the floor.
My advice was not to unscrew those pins but TRY to only remove the screws around the SONY tubes as the MEC.
I'm sure the MEC tubes are fixed with only two top screws so the pulled is very simple also when projector is placed in ceiling. I do not remember if the Sony have four screws.

[cosaw]

Just recently had MEC tubes in and out, while on the floor, for transport purposes. To me it was tricky enough on the floor to get the long rods to thread easily/nicely/first time. On the ceiling this will be harder still. If you cross thread one of those rods and force it then you're screwed because they're tapped directly into the chassi. Also, without the final bridge plate on, the tubes' weight will put a twisting force on the long rods if you just left the tubes hanging - making location of the rods and possible cross threading more of a concern.

Probably won't work but you could try putting the bridge plate in position with the left and right four end bolts loose. You may then just about be able to pass the tubes through and then put the bolts in that secure the tube assembly to the bridge plate - then put the long rods in afterwards.

Last resort - make some sort of rope hammock to hang the tubes from while you put the long rods through. That or a safety net.

Preferably get the thing on the floor.

[barco_75]

Thanks for the tips. I'm going to try to avoid the hassle of pulling the projector down. I devised a pulley system last time to lift it, but I really don't want to miss with the alignment of the projector as it is spot on. I think I might try a mix of the ideas presented. First I'm going to remove the mounts and bolt them to the tubes. Tubes are secured with 4 bolts. Getting to top 2 is difficult and you would have to use a stubby screw to even get it to fit if you try and leave mounts on projector. Second, I'm going to turn the bridge upside down. That will get me an extra 1" of clearance. Then I will remove if needed the cards as suggested by Domenico. I'll insert tube and frame one at a time and bolt tubes to bridge. Then I'll loosen bolts and insert shim below frame and bridge to lift into position. Then I'll install rods. Once all rods are installed I'll remove bridge and flip back the proper way. I can also install a motorcycle net below the tubes before removing the bridge.

Anyhow that is the concept. Or I'll get 4 people on one ladder and join the circus. I'll try soon. Fingers crossed. If it seems unsafe when I try, I'll have to resort to pulling the chassis down.

On a separate subject are the deflection yolks and focus yolks compatible with Sony's? Deflection yolks have the same part # but focus yolks do not. I saw on one post where Curt responded that deflection yolks may not be compatible because Francisco couldn't get his width correct. However, Francisco pulled the yolk back a little and it worked (but this could implode tube if pulled too far). I also see the EHT and splitter do not have the same part number, but I'm guessing the 808g parts are compatible with Sony. Everything else has been switched from a donor 808s has the same part numbers as listed on the cross reference sheet (or even newer version than listed)

[Curt Palme]

Um, when you change your tubes, your alignment goes all to hell.

[Curt Palme]

Um, when you change your tubes, your alignment goes all to hell.

[barco_75]

Ya thats true! The main concern is the mount (and chassis) will will lose its alignment if i remove the projector from the ceiling. It set perfectly square (or very close) and the projector angle is also set where I want it.

[modelaratrod]

I've also got an 808 with ok tubes and a new set of tubes to go into it, but looking @ all that's involved there's no way I would attempt to do it on the ceiling. A few 12 packs of Sam Adams or the like and some pizzas a few friends and it's off the ceiling and back on before you know it. I would index exactly where it's mounted now either by marking the mount or ceiling or even like I index doors and fenders on cars drill an 1/8 inch pilot hole and use it to realign it.

[barco_75]

just reporting...it is possible to switch the tubes without taking the projector down. It's a bitch but it can be done. It didn't go down exactly as I thought it was going to. Barco used every available inch of the old 808 chassis to fit those Sony tubes in. I'm hoping there was be a benefit of using all of that real estate. Will find out soon

[cosaw]

Well done. Let us know if you see a difference.

[barco_75]

Thought I would provide a rough set of instructions in the event someone desires to do the same. These instructions are only to change the graphic 808 MEC tubes and amps to 808s Sony tubes and amps (or to install or remove sony tubes in reverse order would be similar). These instructions do not include all of the other board changes necessary to go from 808 to 808s. You can search my old posts to figure that out.

It's a huge job to change the tubes and amps. I took me almost two full days. During those two days I also added an IRIS 3 and modified the lower bridge and toyed with changing the fans out (which I decided against after reviewing the fan charts). With these instructions, I think you could do it in a day, but don't get mad at me if it takes longer! I was able to change the tubes and amps with no helpers.

1) Remove lens
2) Drop cover, remove amps and then remove MEC tubes. Tubes are secured with two lower screws and top is secured by a slip connection which is not positively connected. If I remember correctly you lift the rear of the tube (by lifting of lower front, don't lift at neck) so the neck tilts up and then it will come loose. The Sony tubes and brackets do not have this design and the tubes are mounted to the brackets with 4 screws at each corner of the mounting bracket. Because of this, you can not install the top screws without some gymnastics which will be described below.
3) remove MEC tube brackets
4) Remove lower bridge which supported the brackets.
5) Modify lower bridge to allow Sony tubes expansion chamber to clear. Or buy new bridge designed for Sony tubes
6) Remove needed cards at rear bay of projector to allow sony tube neck to pass through the openings in the aluminum plate between cards bay and tube bay.
7) Install tube magnetics from MEC Tubes to Sony tubes. I switched the focus yolk because it is a different part number. I'm not sure if this is needed but I assume it doesn't hurt. Do not install amps to neck of tube, but do install the stabilization bracket for the amps immediately behind the focus yolks.
8) Install modified or new bridge upside down. This will lower the mounting point of the brackets so you can install the inaccessible top two screws for the Sony tubes and brackets listed in step 2.
8) Mount one tube bracket on left or right side to the lower bridge only with two fasteners (threaded rod and nut instead of stock bolt). Tighten bracket tight to lower bridge. Do not install rods at top of brackets. I started with the RED bracket. For the fasteners, I would recommend you buy threaded rod with a nut to match the thread of the existing mounting bracket screws. In the next steps you will see why I recommend this.
9) Install Sony tube to back of the one bracket. You will need to pass the neck though the openings in the aluminum plate as noted in step 6. Secure tube with one or two screws into tube bracket at bottom. After this the tube will still sag so you still need to support it with your hand but it will help reduce the weight. In this location you can then install one of the screws in the top of the tube bracket by hand. The top screws are difficult to get to. It will help if you have a flexible socket elbow because you will not be able to place the socket driver (screwdriver type handle) directly square to the fastener. Once you have the tube secure by one bolt at the top and one or two in the bottom, you can loosen the tube mount (two screws in bottom of lower bridge) slightly so you can twist the entire tube and bracket to get better access to the screw at the top immediately against the side of the projector. Do not loosen the tube bracket greatly. The friction of the tube bracket to the lower bridge keeps the tube from sagging and possibly falling out of the chassis.
10. Now you need to install the pins which secure the top of the tube bracket. You can't do this without raising the tube bracket which currently is secured to the lower bridge. This is why I recommend installing the threaded rod and nut (It allows you to loosen the bolts at the lower bridge and keep the tube secured to the lower bridge at all times). Loosen the two lower nut on the threaded rod at the bridge while supporting the tube in your hand. Raise the tube and tube bracket at the way up until it hits the top of the chassis. Place a wood shim between the tube bracket and the lower bridge. Tighten the nuts on the threaded rod. With this tight you should be able to release the tube and it will be secure. Install rod to secure top of tube mount to top of projector chassis. One rod if installed tightly will hold the tube in place, however, I would recommend you place both rods in place until you are ready to install the next tube.
11. Repeat steps 8-10 for green then blue tube (kind-of, see below). Before installing the next tube, I would remove the pin on one side that supports two brackets (between brackets). With the convergence tray removed, I did install one bolt into the threads designed for the pin from the top side to align and secure the existing bracket until the new pin could be installed. To install green and blue brackets you will need to totally remove the lower threaded rod and nut so you can get the brackets intertwined after you secure the tubes to the brackets. You will find you can't lift the brackets vertically because the adjacent bracket will not provide adequate clearance. In liu of this you can slip the two brackets together and drop a bolt in the lower part of the mount that the pin passes though. Then with the bolt installed in the convergence tray you can lower that bolt and once complete the new tube and mount will be secured (but still hold on to the tube). After this step you can install the adjacent pin where the two brackets don't intersect. Once this is secured remove the lower temporary bolt between the two brackets, slip the pin in and then raise the pin up. Slowly remove the top bolt in the frame (immediately below the pin) and turn the new pin into top of both bracket until it is threaded. If you can install the four shinny metal screen at the front of each bracket during this process ( I don't think it is possible, so I didn't and had to bend them at the scheimpflug adjustment to fit)

During this process I used a bungee cord and strapped it two each side of the aluminum frame so the neck of the tube will rest on the bungee (may need to remove plastic side cover to find hole to put bungee in).

12. Flip lower bridge to correct position and secure. The pins securing the top are sufficient to hold the tubes. Be sure the pins are installed tightly before removing bridge.

13. Install amps. You may need to shift the tubes (toe-in toe-out) to get the clearance.

14. Hook up all the wiring, install lens, and covers.

That's it! I know this may be hard to understand so I recommend you practice and understand technique before you try this. As it very tricky and takes some skill to achieve this.