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Author Topic: Conversion - Christie CH20, CK20 to 25 Steve Kathan Film Handler Posts: 1 From: North Highlands, CA, USA Registered: Aug 2001 posted 11-16-2001 09:22 PM                     I'm wondering if anyone has any experience converting Chistie CH's or CK's (we have both) 20's to use a CXL25 bulb. We have several in theatres less than a year old. We have already put Phoenix kits or Strong reflectors in the "CH's" and Xetron reflectors in the "CK's". This has doubled and in some cases tripled the light. We have large screens with top movable masking, our formula for computing lamp size did not take this into account. We use new Schneider lens, have optical clear port glass, 90 degree shutters, and properly aligned lamphouses. We've tried just about everything we can think of but we are still only hitting 6 to 9 footlamberts on flat and 10 to 14 on scope. Trying a larger bulb is one of the few options we have not yet tried. It appears I can get between 90 and 95 amps out of the power supplies which is pretty close to what I need. It looks like I will need a 20mm spacer on the rear bulb support in order to move the bulb back into the reflector and perhaps a larger shield on the front of the bulb to accomodate the larger diameter of the bulb, can anyone think of anything else? I will check for adequate exhaust and add more if needed. It does not appear that there is enough room in the Phoenix kit plenum to pull the bulb back into focus although the instructions indicate it will handle a 2500 watt bulb.? Is this also true for the "CK". If any of you have any thoughts on this I could sure use some help. One last thing, I wonder if a high speed intermittent and a smaller shutter would help, I've read that Kodak has come up with a way of converting a normal (in this case Century) intermittent to a high speed intermittent, any info on that? Price? Availability? Thanks in advance, Steve Kathan.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 11-16-2001 09:33 PM                        The improved "quicker" intermittent and more efficient modular lamphouse developed by Kodak are the subject of a technical paper in this month's SMPTE Journal - Design Improvements for Motion Picture Film Projectors, C. L. DuMont, A.F. Kurtz, B. D. Silverstein, and D. H. Kirkpatrick, Eastman Kodak Co., Rochester, NY. Kodak is negotiating with several equipment manufacturers to commercialize these inventions. They are not yet on the market, although prototypes are operating at some sites. http://smpte2001.iconvention.com/V25/index.cvn?id=10004&p_navID=12 ------------------ John P. Pytlak, Senior Technical Specialist Worldwide Technical Services, Entertainment Imaging Research Labs, Building 69, Room 7525A Rochester, New York, 14650-1922 USA Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243 E-Mail: john.pytlak@kodak.com Web site: http://www.kodak.com/go/motion  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 11-16-2001 09:50 PM                     The best thing to do with a CH-20 is to get the conversion kit from Christie to put the SLC guts into it. This will give you the equivelent of a new Christie console as far as light output. The rectifier is still the same as in the Ch-20. They run under $2,000.00, and installation is very easy to do. Mark @ GTS  |  IP: Logged System Notices Forum Watchdog / Soup Nazi Posts: 215 Registered: Apr 2004 posted 07-06-2005 12:54 AM                 It has been 1327 days since the last post.  |  IP: Logged Michael Wilkinson The Entertainment King of Colusa and Beyond Posts: 89 From: Colusa, CA USA Registered: Apr 2004 posted 07-06-2005 12:54 AM                        This topic is just a bit old. I have a CK20 with a nice reflector and wanted to put in a 2500 watt lamp. I had previously installed a larger power supply and have just replaced all of the diodes. I know the CXL25 lamp envelope is bigger than the 2K....can it be done? Thanks  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 07-06-2005 06:42 AM                     I have no doubt that with enough schmutzing about, you could get a CXL-25 to fit the CK-20....but you will find it is not a comfortable fit and that you will probably have reflector problems with the heat. The CXL-25 fit CK-30s real well...in fact, the CXL-25 lamp is built around the CXL-30 size. Better to convert a CK-30 (or CH-30).  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 07-06-2005 09:54 AM                        I'm basically in the same camp as Steve. Don't do it. Another comment: The Phoenix kit converts the CH console to the same Optics as the CK. The "Strong" conversion converts the CH to a Super Lumex optic. The CK has less light than the Super Lumex. Therefore your best improvement is the Strong kit;which will NOT fit a CK readily. The most light improvementwill be to get correct optical alignment by using symetrical masking or going to a common height system. (One example: 40 ft wide on flat is the center part of a 50 foot wide scope screen: Do you have enough light to light up a 50 ft screen?) If not you are underlit to start with. If you then misalign by having 2 optical centers, you must derate further.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 07-06-2005 12:44 PM                     A correction to Louis...the Phoenix kits upgrade a CH series console to SLC optics...not CK...so if you like the current Christie consoles, the phoenix kit is for you if you have CH consoles. There is no upgrade kit to the K-series.  |  IP: Logged Michael Wilkinson The Entertainment King of Colusa and Beyond Posts: 89 From: Colusa, CA USA Registered: Apr 2004 posted 07-06-2005 01:58 PM                        Fogetting for a moment about the debate on the difference in optics from a CH to CK to SLC... I am familiar with the Stong and Pheonix kits and have installed them in H series lamphouses. This is not the situation that I am dealing with at present. All I'm trying to do is figure out a way to boost the light output just a bit more on my existing CK-20 console. (short or ripping it out and putting in a Kinoton which I know would make Brad very happy) Steve: I have a dedicated 1200CFM fan (excepting static pressure) that keeps the lamphouse nice and cool. The rectifier is a CC25. To refine my last question: Does anyone know if the optics for the CK-20 can handle a CXL-25 lamp or does the size difference put the alignment too far out of range? Has anyone out there done this before? Thanks again  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 07-06-2005 02:38 PM                     I have not done this so I can't say. I would imaging that you might have an issue getting the arc in the right place...it is a matter of getting the CXL-25 far enough back since it is a physically larger lamp. The threaded pin on the negative is the same. The anode pin would be the same as a CXL-30 (which might be the same as the CXL-20, I can't recall.  |  IP: Logged

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