8mm Forum: Converting projectors that use expensive DJL bulbs

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Posted by Timothy Duncan (Member # 4461) on October 12, 2014, 08:57 PM:

Mr. Duncan has chosen to delete his post.

[ February 01, 2015, 11:39 AM: Message edited by: Douglas Meltzer ]

Posted by Steve Klare (Member # 12) on October 12, 2014, 09:29 PM:

I buy EFPs and EFRs which are pretty cheap, so I actually buy three of each at a time and stash them. This is enough for several years.

-one night last week I blew one of each on my two machines: just wasn't my day!

With a scarce bulb, it's probably not going to get any more common, so when you get the opportunity to grab a couple it's probably a good idea to stock up several spares.

If someday you decide you don't need them you'll be able to sell them for at least what you paid and maybe even more.

I don't necessarily agree with the "cool the bulb off with the fan after use" philosophy. When I used to work in avionics we talked about Thermal Shock: rapidly heating and cooling a device so that all the different parts expanding or contracting at different rates tended to tear each other apart.

To me the opposite of that is letting something cool down as slowly as practical and not running a stream of cool air across it while it's still hot.

I remember my Dad doing this with his slide projector, but I think his idea was the lamp was more fragile while it was hot and he wanted it cool before he moved it. (Don't really agree there either.)

(I suspect it doesn't make much difference either way, the filament will fail before thermal stresses take over.)

Edit: I'm seeing these lamps at about 60 bucks a pop where I buy mine. If you take the money for three lamps you can buy a pretty decent Elmo or Eumig sound machine that uses 50 hour lamps you can get for less than 10 dollars (just a thought)

[ October 12, 2014, 10:37 PM: Message edited by: Steve Klare ]

Posted by Dominique De Bast (Member # 3798) on October 13, 2014, 12:49 AM:

Steve I am surprised that you say the filament is not more fragile when it is hot. All recommendations I heard or readed so far said the opposite and all advises are that you should never move a projector when the bulb is hot as it is almost always guaranted that it will blow.

Posted by Paul Mason (Member # 4015) on October 13, 2014, 03:30 AM:

The filament should definitely be allowed to cool off before being moved; probably at least 30 minutes. That said old lamps fed at mains voltage often blow when switched on due to the high level of current when cold. The magnetic forces cause short-circuits between filament turns or snapping at weak points.

Posted by Steve Klare (Member # 12) on October 13, 2014, 08:02 AM:

It depends on what you mean by "hot". The thing is white hot when it's operating, but cools to orange and red and then out in what, two seconds? I wouldn't bang it around while it's operating, but probably if you do a normal take down and then put the projector away a few minutes after you last lit the lamp you are good to go, especially if you remember the whole thing is delicate anyway even stone cold.

You don't let it sit an hour, declare it cool enough and then take it skiing!

I'm saying Dad's post-show ritual made him feel happy, and that's fine. Other than that I doubt it made much difference. I'm also saying running the fan probably put more stress on the envelope than not using it would have, but the filaments died a natural death long before the stresses made a difference anyway.

Posted by Maurice Leakey (Member # 916) on October 13, 2014, 09:44 AM:

Timothy
If the lamps are hard to find now, with high prices to match, why don't you consider the conversion kit. It doesn't look too difficult to fit.
http://www.ebay.com/itm/DJL-Projector-Lamp-Replacement-Module-replaces-expensive-DJL-bulb-Lasts-Longer-/251228589630?pt=LH_DefaultDomain_0&hash=item3a7e640e3e

Posted by Jim Schrader (Member # 9) on October 13, 2014, 11:00 AM:

that is what i did to my B&H i converted the bulb to a cheaper bulb, but i still have some DJL bulbs.

Posted by Steve Klare (Member # 12) on October 14, 2014, 01:07 PM:

It seems like the best solution possible.

You don't have to scrap a good machine and you aren't at the mercy of running on scarce lamps either.

Posted by Joe Vannicola (Member # 4156) on October 14, 2014, 08:50 PM:

I heard of one film collector who bought something like two hundred bulbs for his projector or projectors. No film collector will go through that many bulbs in their lifetime. [Roll Eyes]

Posted by Janice Glesser (Member # 2758) on October 15, 2014, 01:23 AM:

Timothy...I just converted my Sears Du-All Eight (made by B&H) projector from using DJL bulbs to ESD bulbs. I didn't buy the kit since I had the QLV-1 holder already so it was just a matter of drilling a few holes and wiring it up. The kit will give you everything you need to do the conversion with instructions.

[ October 15, 2014, 09:54 AM: Message edited by: Janice Glesser ]

Posted by Steve Klare (Member # 12) on October 15, 2014, 08:32 AM:

It's not that hard to figure out who you know that can do it:

Name a friend or relative that can name the cast of Star Trek and/or Star Wars (bonus for both)

Carriers of pocket knives (-not switch blades) are promising candidates. (The more tools inside the better.)

If you drive past their house and see feet poking out from under their car, that's a good sign. If there is also a pool of blood and no jack there...call for an ambulance.

If you walk up to their front door and see two wires where the doorbell should be and an alligator clip to short them together, this person is no higher than "B" list material. If you ring their bell by breaking a beam of light, NOW we're talking!

If you're at the mall and spy a friend hanging out at Radio Shack, you've hit pay dirt. Sports Authority?...not so much.

If you lived in my neighborhood, I'd certainly help you with it!

Posted by Steve Klare (Member # 12) on October 15, 2014, 09:15 AM:

Janice is kind of an inspiration around here. It's nice to see someone so passionate about well... pretty much anything!

(-at least anything that doesn't involve harming other people! We have enough of that already.)

I'd kind of like my own retirement to be something like hers!

Posted by Ousama Al Balaa (Member # 5135) on December 01, 2015, 04:25 AM:

Actually I am looking for two solutions:
1. The projector speed. what should be the projector speed be for conversion on video and then digitizing by shooting off the screen. The projector I have (when the bulb was working) is B&H 456 with fixed speed. I had flickering on the video. It is posted on Youtube. Ousama Balaa 1952.
2. The replacement bulb that lasts 175 hours as posted on e-bay seems to be a viable option. Has anyone tried it? Does it work? It is sold by Hardluckcharlie.

Posted by Janice Glesser (Member # 2758) on December 01, 2015, 01:15 PM:

I have not used the DJL converter made by George Tveden, but don't see any reason it shouldn't work. George also sells a kit to do the conversion like I have shown above, which is much less expensive than the converter adapter.

In any case however...if you intend to do telecine transfers you should consider buying another projector...one with a variable speed control. You need to run it at around 20fps. I recommend the Sankyo 2000H, but there are many others such as the Chinon Whisper 727...Keystone 2500....Chinon 2500GL...Sankyo 1000 ...Bell & Howell 10MS, etc.

[ December 01, 2015, 02:20 PM: Message edited by: Janice Glesser ]

Posted by Pasquale DAlessio (Member # 2052) on December 01, 2015, 07:20 PM:

A few years back I did a post about this conversion and showed some good photos. I have done it a few times with the kit and with out. Always good results either way.

Posted by Steve Klare (Member # 12) on December 01, 2015, 08:12 PM:

Hello, Pat!

-it's good to see you here!

Posted by Pasquale DAlessio (Member # 2052) on December 01, 2015, 08:38 PM:

Thank you Steve. I am thinking of getting back into the hobby. I have to start from scratch. (but I don't have an itch) [Smile]

Posted by Steve Klare (Member # 12) on December 01, 2015, 08:47 PM:

-Eh!

Do what feels right and enjoy yourself!

-at the end of the day, that's why we are here!

Posted by Jim Schrader (Member # 9) on December 02, 2015, 03:58 PM:

Welcome back pat it was your post that made me decide to convert my unit now I want to covert 2 more.

Posted by Dominique De Bast (Member # 3798) on December 02, 2015, 04:08 PM:

So glad to see you, Pat !

Posted by Pasquale DAlessio (Member # 2052) on December 13, 2015, 12:38 AM:

Great to be back. Thanks for the welcomes and comments.

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