Two cords coming out of Zone VI CL head

[hyperfocal]

I got my Bessler MX-II with an older Zone VI cold light head up and

running. The cold light head had two cords coming out of the lamp

housing. I played around and found that by plugging one of them into

the �enlarger� plug socket of my graylab timer, the timer and lamp

worked. The other cord coming from the head didn�t work with the

timer when plugged in to the �enlarger� socket; but the lamp did come

on when I switched the timer on �focus,� albiet with a dimmer light

than with the other arrangement.

 

My questions are: 1) What is the purpose of two cords coming out of

the cold light head lamp housing? Is one for some Zone VI voltage

compensting contraption? 2) What is the �start� plug in socket on

the timer for? The safelight?

 

THX in advance for any insight.

 

H

[alec1]

I'm surprised you got the lamp to work with both plugs. Are you real sure the lamp works with both??? One is for the lamp itself. To test it, plug one into a wall socket. If it immediately operates the lamp, that's the one to plug into your timer. The other is for the heater built into the head. The cold light produced is far more consistent when the head is warm, thus the heater. When using the head, that cord should remain plugged into a wall socket the whole time - in fact, it should be plugged in 15-20 minutes before you start to get the head warmed up to the proper level before printing.

 

I would guess that the one where the lamp was dim is the one for the heater. That plug is not normally grounded, while the one for the lamp is. Hope that helps.

 

The start plug is probably where the grounded plug goes. You can plug a safelight into the other socket. The timer should light up the safelight until you start the exposure, at which time, it will cut off the safelight. Before the exposure, by using the focus feature, you can light up the lamp to focus the negative w/o starting the timing circuit.

[m0002a]

Just to clarify what Alec has said, leave the thermo cord "heater" plugged in to a unswitched outlet (always hot) throughout your entire printing session, but unplug it after you are finished. Make sure it is on for at least 10 minutes before you start.

 

The early Zone VI heads did not have the built-in photocell for the compensating timer. If yours does, you can see it near the lamp grid and there would also be a round DIN socket on the top of the head. You can purchase a photocell for about $55 from www.calumetphoto.com and install it yourself if you have the Zone VI Compensating Enlarger Timer or the (discontinued) Zone VI Stabilizer.