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Author Topic: Lamp Question Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-12-2007 07:44 PM                     I have a LTI Helios 2k lamp running on a Strong 6280005 model switcher xenon power supply in a Super Highlight(1988) console. The lamp had been operating fine up until last week when I was doing my weekly check on lamp operations (hours count, steady arc, amps, volts, clarity of the envelop)when I noticed that arc on this particular lamp was over shooting anode. Since the show was running there wasn't much I could do other than try increasing/decreasing the amperage a little bit to see if that would bring the arc down, but no go. So I set the amperage back to where was previously (70amps by meter). I came back about 30 minutes later to check the arc again, and this time the arc was centered and steady. So now I'm thinking that it corrected itself. I came again a little while later and this time the arc was over shooting again. When the show ended I fired the lamp up again let it heat up checked the arc and again it was over shooting. Shut off the lamp adjusted the stablization magnet upwards to try and pull the arc down, but no good. Reset the magnet let the lamp cool down and then rotated it 180 degrees. Fired it back up and still over shooting the anode. I then decided to check the amperage/voltage with a hand held meter: 69 amps at the shunt and 26.5 volts off the rectifier leads both within spec. The lamp has about 950 hours on it and is very clear. Before I warranty this bulb is there anything else that I can check? There are still times when I check the arc and it will be centered, but most of the time it is over shooting the anode. As a side note, I have been using Helios lamps for a little over a year and have had almost zero problems (I had one explode with only about 1 hour use on it; had the warranty honored (got a new lamp and reflector within 2 days), but other than that zilch. I have been getting right around 2100 hours use on them before I get excessive flicker.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-13-2007 10:05 AM                     LTI Lamps have been getting better and better slowly... At the AMC locations I service they use LTI exclusively and they have typically been running way past rated hours. The only thing I still see that I don't like is extreme darkening of the envelope. They still have some homework to do... or patent liscencing of others to get and adapt. There are a few Helios's in my area and they seem to be good for the most part. Two things to consider... have you rotated the lamp as recommended... this is a good thing to do on lamps larger than 2kw since the electrodes are quite heavy and can sag just slightly if left in one position for the life of a lamp. Also is the arc stabilization magnet still good. I typically find that Strong Lamphouse magnets become weak over the years.... this is very true in Super-Lum-Ex lamphouses. Also if you see some overshoot or horse shoeing of the arc when running with Strong Switchers try a new stabilization magnet or at least make sure its installed correctly. Strong Switchers seem to exhibit this phenomonon for what ever reason and its not tied to a particuluar brand of lamp. Have seen this with all brands mof lamps on occasion since the appearance of the compact switchers. New magnets seem to help solve it. Mark  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-13-2007 12:20 PM                     Thanks Mark. I The thought of the magnet being had crossed my mind, but what I don't understand is that sometimes the arc will be centered and steady for a period, although short. I would think that if the magnet was weak the arc would always be over shooting. All my lamps are 2k and I do rotate as recommended. The envelopes on the expired bulbs are usually very clear or with some light darkening.  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 퍼항시, 경상푹도, South Korea Registered: Mar 2007 posted 04-13-2007 02:34 PM                     In an "ideal" situation (not ideal for you, ideal in the sense that it follows exactly as predicted all the time) if the magnet were the only problem yes it would always overshoot. But if it's a combination of issues, then it won't. The arc won't always shoot to the exact, exact same spot (with or without a magnet) so there's gonna be some variance in where it goes. The company's QC attempts to minimize the variance but it'll always be there. Hell, this'll happen to a small extent even on the more expensive bulbs. And I seriously doubt LTI will go the route of paying for licenses for patented technology from, say, Osram as that would make their bulbs shoot up in price suddenly.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-13-2007 02:38 PM                     Its pretty obvious that their "getter" is seriously lacking... they may not have a choice but to use someone elses patent in that department. Most are used to lamps staying clear to the end of theor lives today. At any rate the LTI's are still miles away from offering the customer the most return for the dollar spent. Mark  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-13-2007 04:11 PM                     quote: Jeremy Weigel I noticed that arc on this particular lamp was over shooting anode. Interesting, that I've had the same experience when using LTI bulbs as well when they were in usage after a few months..esp, in using the standard LTi's that I could only get 1200 hrs on an average before they went all bad with horrible flickering - and the warranty hrs for a standard bulb is at 2400hrs ... and we couldn't get warranty afterwards ... (bad bulb supplier..) quote: Jeremy Weigel I have been getting right around 2100 hours use on them before I get excessive flicker. I tried a 2k LTi Helios in a STRONG X-90 console (basically a Super Lume-X in a cabinet..) and managed to grab 2300hrs off that bulb before it began to display bad flickering and hard striking-anode plug showed severe cracking and those three ripple 'horns' on the end(I know,I have old rectifiers..) -but nothing compared to a Christie that I had in there before. which had 5600 hrs on the bulb and hated to pull it out - good exhaust, envelope clear, no hard strikes, just the typical looks of age on both cathode and anode plugs in the envelope ... (sorry, no more LTI's for me...) -Monte  |  IP: Logged Bernie Anderson Jr Master Film Handler Posts: 435 From: Woodbridge, New Jersey Registered: Apr 2000 posted 04-14-2007 04:17 PM                        We were told to run LTI bulbs at 90% of their max wattage, don't rotate the bulb at all and remove it at the set max hours. I'm running 3K which gets removed at 2000 hours regardless if it still is good. And 4.5K that come out at 1500 hours. If you're in an AMC, make sure that they come out by the max hours that they set. Its so that if the bulb has a problem, its under warrenty.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 04-14-2007 04:47 PM                        At the Embassy, someone recently pulled a badly flickering LTI 2k (with something like 1500 hours on it) and replaced it with the only spare (an Osram with 4000+ hours and almost no blackening). The picture now looks great, but I hate the idea of using a bulb that old. Meanwhile, Landmark is now paying about twice as much per hour for LTIs as it was for Osrams (which gave better light anyway). Way to go.  |  IP: Logged Bernie Anderson Jr Master Film Handler Posts: 435 From: Woodbridge, New Jersey Registered: Apr 2000 posted 04-14-2007 05:48 PM                        I heard a rumor that we're chaning back to Osram. Only heard that once, though.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-14-2007 06:14 PM                     quote: Scott Norwood The picture now looks great, but I hate the idea of using a bulb that old. I know what you mean there Scott, but try me with a Christie 2k with 6200plus hrs and I hated to pull it when it still gave me wonderful light, no darkened envelope, and strikes first every time. But, when I pulled it on a change then took it outside to bust it, it didn't pop, just simply shattered lamphouses I really do like were the ones that used vertical bulbs - could hours be had with bulbs in the vertical position.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-14-2007 09:57 PM                     I have photos of the past three Helios I've taken out and would like to share them, but simply can not figure out how to upload images. I tried the "image" button and pasted the url from photobucket, but got some angry looking dude with a warning message instead. Tried copy and paste of the image itself, but no go. What am I missing?  |  IP: Logged Adam Martin I'm not even gonna point out the irony. Posts: 3686 From: Dallas, TX Registered: Nov 2000 posted 04-14-2007 10:53 PM                     You could do one of two things: 1. Read the FAQ. 2. Click the "Click here to upload an image" link on the page where you type your post.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-15-2007 08:31 PM                     Sorry didn't see the "Click here to upload an image." link. I was too concentrated on the "image" button below. Just out of curiosity, what the "image" button for if we're not allowed to use a photo storage sevice such as photobucket?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-16-2007 12:52 AM                     quote: Jeremy Weigel what the "image" button for if we're not allowed to use a photo storage sevice such as photobucket? Images stored here on FT has to be a certain pixel range (500 pixels either vertical or horizontal) and those outside services storing images are usually larger than what is required here on FT. If you want to place an image here on FT, it has to follow the FAQ rules to be properly displayed. Also, importing images from an outside source like photobucket, those pics could be imbedded with viruses, whereas importing pics from the local host computer has a much lesser chance of being imbedded with a virus. ..it's basically all for security reasons.. *gasp* those famous "Helios" bulbs -Monte  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-22-2007 07:34 PM                     Finally figured out how to reduce pics. Here are pics of the last 3 LTI Helios I pulled with their hours used. As you can see they have relatively clear envelopes very little anode/cathode wear. [ 04-24-2007, 12:08 AM: Message edited by: Jeremy Weigel ]  |  IP: Logged

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