CurtPalme.com Home Theater Forum

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Guys

https://www.youtube.com/watch?v=E1Hd1OwWgsI

MTBF? "about twenty minutes"

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

But does it have an HDMI input?

larryp · Joined: 24 Jan 2012 Posts: 252 Location: eden prairie mn

Ceiling mounting that thing would be a royal pain in the butt

Zolzar · Joined: 26 Jun 2009 Posts: 252

40k volts = xRay. Crap! Should I be concerned with my marquee or 10PG?

That is so cool. "Customer convergence circuits" pumping out plenty of wave forms for geometry adjustments. Love this stuff.

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

34.9KV = x-ray generation. 40KV = more x-ray generation.

Why do you think there's lead shielding on EVERY CRT projector? It's not there to make the projector heavier!

While CRTs are not designed to be optimal x-ray generators, they do generate some x-rays and there is a relationship between
anode voltage and x-ray emission. X-ray emission increases MORE rapidly than anode voltage increases.

For example, a 10 percent increase in anode voltage will cause MORE than a 10 percent increase in x-ray generation. It may
be as much as a 40 percent increase.

**Curt Palme** · Posted: Sat May 14, 2016 10:27 pm Post subject:

I used a very similar, but larger CRT projector using this technology for Wrestlemania 2 in 1987. Each CRT looked like a jet turbine, about 150 lbs each, and the all tube chassis sat behind them. The image was awful, the following year Wrestlemania 3 used GE Talarias, but that beast from 1967 or so was a sight to behold!

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

Speaking of oversized projectors, has anyone here actually seen a Barco 912 in person?

What kind of tubes do they run?

**Curt Palme** · Posted: Sun May 15, 2016 2:47 pm Post subject:

I saw 3 of them. Offered them up here for sale cheap about 18 months ago, but there were no takers, so they went to the scrappers. Panasonic tubes, REALLY big ones, insane sized lenses. The projectors worked, had a bit of wear, one had a spot burn, but I wasn't going to pay $1500+ shipping from San Fran to me if there were no takers. There weren't, sadly.

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

Darn, missed it!

I would have LOVED to get one of those beasts just because.

Tube type is P19LCR07(HKA, RJA, BMB) and I can't even imagine if anyone would stock tubes of that type. What else were they
even ever used for? Other than the Panasonic 12" machine.

I'd have killed (or at least, seriously wounded) just for the lenses!

Keep me in mind the next time you should ever encounter one. If you ever do. Because I may have to pay on an installment
plan, but I want one.

The idea of making a Marquee 10500LC Mega certainly appeals to me, if I could just get the tubes and lenses.

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

Speaking of old tvs, I was watching a documentary on WWII the other night. Operation Aphrodite used radio controlled planes to fly into their targets. They were essentially the first drones. The planes had to be flown by a pilot first before he jumped out. Then the remote pilot would fly the heavily bomb laden plane into the target. They used TVs and remote control to pilot the plane.

They showed some video using the equipment and it was good enough to make out basically where you were going.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Guys

About eleven years ago a Hughes jet ski projector was for sale here in Phoenix, asking $4000, damn I was tempted to acquire a new toy. The only reason I declined was the need for a 240v outlet to power the damned thing.......

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

The jet ski/blue whale? Interesting beasts. CRT driven light valves, like the AmPro 7000s but three complete optical paths with lenses was excessive. AmPro's optical engine was a superior design. But the Hughes light valves didn't have the problems that AmPro had with theirs.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

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

The "black is grey" issue with the AmPro/Greyhawk light valves was just the state of the art at the time. It wasn't a "problem",
it was "the best we can do" in 1998.

The big problem with them is that when AmPro bought Greyhawk, an engineer who thought he knew more than the Greyhawk engineers who were making excellent light valves decided to change the sealing procedures because "You don't have to do all that, and this is cheaper" and every one of those seals started to fail after about 150 hours of operation in this fairly high temperature environment inside the projector. When the seals failed, two things happened: Liquid crystal leaked out, and bacteria that feeds on liquid crystal got in and turned the light valves into petri dishes. With visible results. It became less a video projector and more and more a laboratory experiment with a built-in microscope.

That's what killed the company. When it cost 25K to replace 3 light valve assemblies and you have to replace them three times
in a machine that sold for only 70K, and all the replacements are made wrong just like the originals, you soon find that your
shirt is gone and your arse is hanging out in the breeze.

All because somebody thought he knew something better than the people who built it and made it work.

Well, stupid has a price. That one was rather high.