Difficulties with Beseler 45-S Head

I recently purchased a Beseler 45-S dichroic head off EBay. I want to use a color enlarger for VC printing. But, I've encountered two difficulties.

>> Even after it's warmed up for a few minutes, there can be anywhere from no delay to three seconds before the light comes on and after starting the timer.

>> The fan vibrates the head. I can tell this, because if I place my hand on the top of the head, I can feel the vibration go off and on as I turn the head off and on.

As to the first problem, I've installed an extra sensor, and I'm using the Zone VI compensating timer. I know this helps a lot, but I'm not absolutely sure that this setup gives me the consistency that I need. Even a few tenths of seconds can make a difference in the highlights.

As to the second problem, I'm using the Zone VI Type I enlarger with a Beseler adaptor, and the enlarger stand sits on concrete and is anchored at the based and at the top. So, the enlarger is pretty rock solid. But still, the vibration worries me. My other thought is to splice a switch into the fan circuitry and turn off the fan when the print is being exposed. But, this shouldn't be necessary.

Do other owners of a Beseler 45-S experience the same problem? What's the cause? While I may have work-arounds, I'm interested in hearing other people's opinions and recommendations.

I have 2 Beseler 45 S heads. They are instant on/off although sometimes there is a faint, brief fade of light when the lamp goes off. Some of the people here know the electronic details and might be able to suggest fixes.

The fans on mine do not produce any significant vibration. There is an article in the "Articles" section by someone who rigged up an external fan to minimize vibrations. If you have a lag before the lamp starts up, that is messed up, but you might just put a piece of mat board over the print for the first 10 seconds of elapsed time and then remove the card at that point with the lamp lit.

I would not recommend disconnecting the fan during exposure. The lamp generate a lot of heat and you will likely damage the unit.

I have two, one is dead and one was dead, both were instant off. One I took out the electronic circuit boards which were beyond repair and replaced the halogen light with a similar color temp and wattage bulb with one that was 120 volts. I remounted the fan with new rubber standoffs and wired it separately and run it off of a timer. The bulb is connected to a Sola CV unit. Now it works perfectly with no hesitation and I have several bulbs for backup.

The other one is sitting on a shelf in my shop waiting to be rescued. I once entertained the thought of making an LED head out of one but gave up that idea when I found out what was involved. I don't use my Aristo cold light head anymore with the Beseler 45MCRX but have it for a backup.

Neil my work around was to gut a unit and rewire it for a 120 volt bulb to replace the 82 or was it 83 volt Beseler bulb. The Sola Constant Voltage transformer cleans up the input so it has clean current.

For the fan I made sure that the rubber was good and there was no interference to the fan housing. I cleaned the vents while I was reassembling.