Problems with Altman 6x9's

[bwhiteford]

Hey all,
I was working on the lighting for our upcoming show today, and as it's a bigger show i'm starting to pull some of the lights out of storage that haven't been used in a while. Theres two major problems I noticed.

Number one (I noticed this in two different cases):
Two fixtures with the same lamp, same lens size (6x9), and plugged into the same circuit have two completely different color temperatures. How is this possible?

Number two (Also noticed twice):
The end cap for these Leko's has a bi-pin base for the lamp with two plastic coated wires heading into the bottom of the base. I noticed one today where both wire jackets were melted and had obviously shorted as there was a dark black ring on the metal close to where they were melted. The other one I noticed was in the early stages, and the plastics of the two wires had melted together to form one, and once I pulled them apart the wiring inside became exposed, so clearly I won't be using that anymore. The wiring seems to be permanently connected to the lamp base, so what can I do to fix this?


Thanks as always!
Brooks

 

[icewolf08]

Number one (I noticed this in two different cases):
Two fixtures with the same lamp, same lens size (6x9), and plugged into the same circuit have two completely different color temperatures. How is this possible?

As incandescent lamps age they can change color temp. There are also differences between batches of lamps. Are you sure that they are exactly the same lamp, because there are many similar varieties of medium bi-pin lamps that are suitable for use in that type of fixture.

Number two (Also noticed twice):
The end cap for these Leko's has a bi-pin base for the lamp with two plastic coated wires heading into the bottom of the base. I noticed one today where both wire jackets were melted and had obviously shorted as there was a dark black ring on the metal close to where they were melted. The other one I noticed was in the early stages, and the plastics of the two wires had melted together to form one, and once I pulled them apart the wiring inside became exposed, so clearly I won't be using that anymore. The wiring seems to be permanently connected to the lamp base, so what can I do to fix this?

The only way to fix this is to replace the lamp base. The base with leads is all one piece. The degradation of the leads is probably due to the use of higher wattage lamps than recommended.

 

[JChenault]

Another possibility - depending on how old the units are you may have lenses with different tints to them. If you have two units that are different try swapping the lenses and see if the color stays with the lens or with the lamp. If it stays with the lamp you probably have different color temprature on the lamps, and you could replace lamps to fix this. It it stays with the lens, you either live with it or get new lenses.

John Chenault

 

[bwhiteford]

Great guys, thank you so much already!

 

[Sayen]

Double check too that the lens and reflector are clean, and that the last cleaner didn't leave any fun coating behind.

 

[RTDesigns]

You may have a lamp in one of the units that is going into its Nova stage before going out. I would suggest changing the lamp to see if that helps.....also try cleaning the lenses as mentioned earlier. I also saw some lamp bases on e-bay the other night...they had a little age on them, but it might get you by for a while until you can afford to replace with new ones.

 

[Les]

Might I also suggest Bench Focusing both instruments?