A little help with the Beseler Dichro 67

[ratmandu]

Hello all, I have aquired a Beseler Dichro 67 that requires a power supply to drop the voltage for the bulb to 30V (it's the old model). I have noticed that the newer models do not require the power supply, and take an 82V bulb. The beseler manual for that system also shows nothing in-line between the bulb and power cable.

Can anyone with one of the newer models take some pictures of the inside, and verify that there is nothing in-line between the power cable and bulb? I'm planning on simply converting mine over to use the 82v bulbs. I have tried using a couple of 12V bulbs (which are plentiful at home depot) along with a small ballast pack made for landscape lighting/track lighting, and they just simply aren't bright enough to be of any use at all.

Before I go and wire 120v up to an 82v bulb, I just want to make sure theres not actually anything in there that reduces the voltage.

 

[MattKing]

I have the older model, with power supply.
As I understand it, there is power supply circuitry incorporated into the newer heads. There is at least a rectifier (part number 90 on the parts list).

From the Beseler website (emphasis added):

67 S Dichro Colorhead
67 S Dichro Colorhead filled with features such as continuously variable 0-200cc dial in filtration, white light filter retractor lever, integral solid state power supply, and interchangeable mixing chamber are included to provide optimum illumination for formats from 8mm through 6×7. The lightsource is ready to be mounted on Printmaker 35 and all other 6×7 series enlargers.

 

[ratmandu]

Thanks for that Matt, I don't know why I didn't notice the rectifier in the drawing/parts list. That makes a lot more sense now, since half wave rectified 120Vac is ~83Vac.
For now, i've got an inexpensive 75W 12V bulb on the way, which will work with the current transformer/ballast i've got installed now. I'll update if It works well.

 

[MattKing]

Thanks for that Matt, I don't know why I didn't notice the rectifier in the drawing/parts list. That makes a lot more sense now, since half wave rectified 120Vac is ~83Vac.
For now, i've got an inexpensive 75W 12V bulb on the way, which will work with the current transformer/ballast i've got installed now. I'll update if It works well.

You are not likely to get what you need from that.
The reasons to spend the "big bucks" on the correct projector/enlarger halogen lamps are that they give good consistency through their working life, and dependably even light. Whether you are doing colour printing or variable contrast printing, the likely variation of the 12V lamps will drive you crazy with changes in colour/contrast and light output, and will vary from lamp to lamp in how even their light is.
My experience has been that the internet sources for the correct bulbs are fairly reasonable in cost, and that if you have a spare bulb at hand the bulb in the enlarger will last much longer (must be a subset of Murphy's Law).

 

[M Carter]

There is almost always a 67c color head on eBay for fifty bucks or so; just check the photos for a regular household plug (often the seller shoots the ID plate as well). (If you're not into DIYing this anyway). Almost bought one several times, but ditched the 67 for a 4x5.

 

[MattKing]

Be careful about those "regular household plug" versions. There is actually several versions of the head, and at least one uses a regular household plug, but requires it to be plugged into a voltage adjusting power supply. I know, and have had the burned out lamps to prove it.
A stupid design (IMHO), but they are there.

 

[ratmandu]

I went ahead and got a Eiko EYF Bulb, got it installed, and made a few prints, comparing them with prints made on the 67 condenser head. I can't really tell any difference between the two, in terms of contrast/quality.
I'm not planning on doing any color prints (at least not for quite a while) with it, so I feel like this $20 retrofit with parts from amazon is going to suit me just fine.

I used this transformer: https://www.amazon.com/gp/product/B00ALU0T6Y/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
And this bulb: https://www.amazon.com/Eiko-EYF-Spot-GU5-3-Halogen/dp/B000297MD2

This makes it actually usable, which is what i'm aiming for. I'm not looking for the most stable light source on the planet, just something that will expose paper properly without too much exposure time, with the ability to use the filters for contrast adjustment on VC paper.

Thank you to everyone who responded!

 

[AgX]

You are not likely to get what you need from that.
The reasons to spend the "big bucks" on the correct projector/enlarger halogen lamps are that they give good consistency through their working life, and dependably even light.

If you refer to halogen lamps, the dedicated lamps employ the same technology as the household ones. They will not gain more consistancy.

What may be different:
-) filament orientation (axial, not transversal)
-) slightly overrated for higher colour temperature (but that would reduce their working time)