Film-Tech Forum ARCHIVE: Hobbyist A-chain in San Diego?

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Posted by Jim Henk (Member # 3628) on 08-31-2013, 10:31 PM:

Hi.

I've got a newly installed, never aligned Kelmar ATD-1274-JJ in a restored Century JJ, feeding into a CP-650, and the guy who has been saying he'll come out and bring the scope to get things aligned just isn't going to be able to find the time. Yep. Things happen, all right. Understandable.

So I'm wondering if there's somebody else in the Southern California area who might wanna come out and basically do a service call. This is a machine currently rollable into place in a garage opposite a slide-into-place screen, so nothing fancy. The speakers are even (temporarily) Radio Shack specials, so, as you can guess, I'm just looking to get it working at all. No socks-knocking-off here for the time being. That's in the future.

There are also a couple of lamphouse issues, (Christie H-10) so, optionally, we could talk about that.

I was always on the relief board, (late 70's and early 80's) so I never was able to get anybody to teach me this stuff, and I'm really interested to learn.

Anybody interested? Thanks.

- Jim Henk

Posted by Craig Huegen (Member # 7666) on 09-03-2013, 01:39 PM:

Do you have the basics working at all?

I have a garage implementation as well on a Simplex XL/SH-1000 and penthouse BACP, with CP500. It took me a while running test loops made with old trailers, but I was finally able to get everything dialed in fairly well, first with a mono cell then a stereo cell, all without a scope. Eventually I'll just go borrow one and make some final tweaks, but for now it seems to work well.

...or is it so far off it's going to require "square one" guidance?

As for lamphouses, mine is also an H10. I built a custom power supply for it. Happy to help with your questions there, too.
http://www.film-tech.com/ubb/f1/t011497.html

Posted by Craig Huegen (Member # 7666) on 09-03-2013, 01:40 PM:

Edit: Grr, for some reason it double-posted.

Posted by Jim Henk (Member # 3628) on 09-04-2013, 03:30 AM:

Square One. No signal passing at all. I know the CP-650 is fine, as I had a Christie projector hooked in, and it sounded okay. (well, considering those speakers and having the projector in the same room as the screen - but it's all been just functionality tests, after all...)

The H-10 - I think that's going to take some on-site observation and debugging. Very dim shadowy image, and yes, the bulb is fine, and the diodes in the rectifier were recently changed. Just not passing satisfactory light. Shutter is timed fine. Even used an Align-O-Tron to make sure everything was just so. It is definitely not just so. I need a trained eye on this.

Posted by Leo Enticknap (Member # 534) on 09-04-2013, 10:23 AM:

Condition and/or alignment of the lamphouse reflector? Lens element worked loose and shifted in the barrel (is the dim and shadowy image present with multiple lenses, and/or do you have the problem if the suspect lens is used in another projector)? I once had a dim picture problem at a little arthouse place back in the '90s. After weeks of hair-pulling about it we borrowed a modern Isco lens from another theatre in the chain, to try in place of the 1960s Taylor-Hobson thing that had been in use for 1:1.85 since, well, the '60s. It was the difference between night and day.

Posted by Craig Huegen (Member # 7666) on 09-04-2013, 11:30 AM:

Yikes. Hopefully someone can help. In the meantime, have you done the good old low-granularity tests, such as the flashlight test (run a small but bright flashlight quickly back and forth across the solar cell to see if you get a rumble out of the processor/speakers), or the white card test (in place, quickly move a card back and forth to interrupt the exciter lamp, where you should hear a rumble / see the signal indicators jump)? If you can't even get that, you may want to give it a once-over before having anyone stop by to look at alignment issues.

As for the H10, mine had a very grimy reflector and dowser lens when I received it. Have you isolated it to the lamphouse vs. the projector? Is your bulb drawing the right current (45-50A)? Is the light a bright white as it hits the back of the projector / shutter, or is it a darker, muddy color? If you remove the projector's lens, do you see the round image from the reflector with the dark spot/silhouette of the bulb & electrodes on the screen (assuming yes since you said you used the alignment tools already).

Sorry if some of this seems basic, just walking through the steps I took from square one as I reassembled and refurbished the equipment I had.

Posted by Scott Norwood (Member # 30) on 09-04-2013, 12:59 PM:

I find the "no sound" problem to be curious. If you power up the CP650 (but leave the amplifiers off!), set the input gain to the midpoint, select format 01, and shine a flashlight (as mentioned above) back and forth across the cell, do you get _no_ signal in the center channel (as measured on the CP650's LCD)?

Is the correct projector input selected? Solar cell cable wired correctly the DB9 end and at the Kelmar reader? Is the power supply for the Kelmar reader good? (The BACP readers have little status LEDs that make troubleshooting something like this much easier.) If the wiring is correct and the reader and processor are both working, you should be able to get at least something out of this system, even if the alignment is completely off.

The A-chain alignment process is described well in the Dolby manual, but it really does require the test films, scope, and RTA to do it properly.

Posted by Manny Knowles (Member # 1171) on 09-04-2013, 01:40 PM:

Gosh! I wish I still lived in Southern California -- this sounds like a fun project for somebody to tackle.

Posted by Louis Bornwasser (Member # 3063) on 09-04-2013, 02:51 PM:

Christie H series lamphouse have a built in gotcha'. There is a stack of spacers just above the bulb adjusters to allow for the different focus points of 1k and 2k bulbs. The affects the for/aft adjustment range. it is also possible to "mount from the other side" to adjust further.

As regards the audio: Do digital first. Remove back of camera, put white card behind, and then tune LED for maximum brightness. Reassemble camera; you should have usable signal.

Use lateral guide adjustment to get the scope trace as in the book. Slight tweaks for azimuth and focus and you are done.Set video level with led current adjust.

Don't mess with any of these adjustments when you do analog. louis

Posted by Craig Huegen (Member # 7666) on 09-04-2013, 04:27 PM:

I thought that the H10 was 1K only... but I could be wrong.

Posted by Louis Bornwasser (Member # 3063) on 09-04-2013, 09:57 PM:

Correct, but the optical bench was used up to 3000 watts. Worthless over 2k. louis

Posted by Jim Henk (Member # 3628) on 09-05-2013, 12:35 AM:

Think what I'll do over the weekend is:

a) sound pickup - try the flashlight on the pickup, go back over the wiring a fourth time, and try the digital pickup to see what happens, like Louis suggested.

b) lamphouse - Lens change makes no difference. And it's not the projector. Again, timing is fine, and there are no obstructions. The Align-O-Tron showed the alignment of the lens shaft to aperture plate is spot on. I'm thinking of banging my head forcefully against the garage door for a while. No... no... although I have plenty of Asprin, it still doesn't accomplish much... Punt. Closer... One thing at a time. Back to step a). There *are* worse things in life.

BTW Craig, yep, no nice round light on the screen with no lens at all. It's either the lamphouse, or the pedestal somehow, but then, alignment tests should have shown that.

But it's really hot and humid here (for us...) so I'd have to open my garage door for air at night, and that's not a very smart thing to do in this neighborhood. (I'm looking to move in the late Fall / early Winter) So the weekend it is.

Posted by Craig Huegen (Member # 7666) on 09-05-2013, 10:27 AM:

On the Simplex projectors you have enough gaps to see the quality of the light exiting the lamphouse... I have found on my H10 that the dowser closing mechanism can work its way loose, so that the dowser plate remains half-closed. Work the mechanism with the side cover off to see if it's not clearing the snood? Also, did you look at the quality and cleanliness of the reflector and the snood glass?

Posted by Leo Enticknap (Member # 534) on 09-05-2013, 11:18 AM:

quote: Jim Henk
b) lamphouse - Lens change makes no difference. And it's not the projector. Again, timing is fine, and there are no obstructions. The Align-O-Tron showed the alignment of the lens shaft to aperture plate is spot on.

I'm not familiar with that model of lamphouse, but the reflector is the only thing left I can think of ... except for one off-the-wall long shot. I once had a lamphouse problem (lamps were blackening and failing after only 500 hours or so), which after much wailing and gnashing of teeth turned out to be a failed ammeter on the rectifier: it was showing a much lower current than was actually being delivered. If you've got the reverse going on (say, it's showing 60 amps when it's actually only delivering 35), that could explain the dim picture.

quote: Jim Henk
But it's really hot and humid here (for us...) so I'd have to open my garage door for air at night, and that's not a very smart thing to do in this neighborhood.

We visited the San Diego Zoo on Sunday and my shirt was drenched after only about an hour of walking around! If it's any consolation, the Inland Empire is even hotter: overnight low of 91 in the back yard in Loma Linda last night. It's a lot less humid, though.

Posted by Jim Henk (Member # 3628) on 09-09-2013, 02:47 AM:

Weekend verdict:

Soundhead - wiring verified again. Traced with VOM all the way from the the pickup wiring connection to the CP650. All leads are correct with no stray shorts or anything. Connection placements verified again against the docs. (both CP650 and pickup) There isn't enough clearance to get in and shine a light straight on into the reverse scan cell or the camera for the digital, but waving a very bright flashlight in the area in Format 1 doesn't make a sound. Nuthin. Ran a spare reel of a Star Trek film - Nuthin. Reversed the pickups at CP650 in case the wrong projector was selected. Nuthin. Connected the Digital and ran Reel 7 of The Two Towers. Nuthin on any format. Went through the options and Auto Digital *is* enabled. Nuthin. LEDs shining brightly, and I read a good 15V to the pickup power inputs. Power supply has all lights active and no complaints.

I got nuthin on nuthin.

Lamphouse: A friend of mine is selling me a pair of Super Lumex's with rectifiers next weekend, so let's try a swap-out and see what happens. In the meantime, lamphouse dowser doesn't *quite close* all the way, but it definitely opens wide and says "Ahhh". Ammeter? Before I start in on that, I'll see how the new lamphouse works.

And yes, my head hurts. But I think the Asprin is helping.

Posted by Craig Huegen (Member # 7666) on 09-09-2013, 10:00 AM:

On the sound? I got nuthin' either. Sounds like it's a have-a-beer-and-troubleshoot time for someone local.

Lamphouse - good luck with the new lamphouse. The H10 & H20's are pretty simple, they're great workhorses. Only problem I've had to speak of have been ignitor troubles. Those HV striking transformers don't last too long if the delay relay sticks and you have a bad bulb, which has happened to me TWICE. At least I don't have those damn tubes in mine.

Posted by Jim Henk (Member # 3628) on 09-15-2013, 10:16 PM:

Meanwhile, back at the ranch...

Anybody available to do a service call and see if this sound challenge can be diagnosed and maybe A-chained? I'll be able to pick up the new lamphouse(s) in early October, so I'll deal with that as it comes. It's this soundhead that's so weird.

Thanks.

Posted by Jim Henk (Member # 3628) on 09-24-2013, 06:08 PM:

Found a guy to down from Hemet who's been around for some time. His name is Gary Wallace, and he's doing a great job. I think his rates are pretty customary, too.

Soundhead - yep, it was just so far out - never been aligned at all - so out came the test loops and dual trace scope. The regular optical sounds very nice now. Dolby Digital kept getting lost until he discovered that there's a spring loaded clip missing from behind one of the rollers. Techs here know how critical the alignment of the film has to stay for Digital, and that wasn't really happening. Will have to come back with that part. Cheap ten cent part, but maddening if you don't have one with you. But the fantastic news is that the pre-amp on the pickup is fine and *won't* need to be replaced! YAAAAAAYYY! Wasn't looking forward to trying to track one of them down.

Lamp house problem was just the cheap badly re-coated mirror. Gary said he had a bunch of lamphouses, and would go cannabalizing. After much playing, got a half-way acceptable image out of the projector as is, but with a *really nasty* hot spot in it. Said distance from bulb to gate might be an issue, too. Will have to look that up. Since I'm picking up two Super Lumexes in a couple weeks, I'm only looking to clean this Christie up for it's next owner. Always leave a campsite cleaner than when you found it.

We talked about a few other things, but he really seems to know his stuff. He's trained some names I know, and now he's even being asked to do digital installs around the country. (New York, etc.) So yes, he travels.

If anybody would like his contact information, let me know. We're not supposed to post that kind of stuff here; am I right in that?