Beseler Universal 45 VC Head

Thread open to any comments, questions, troubleshooting, etc on this head if you are interested.
I have been using this head with VC controller for about two years and putting up with its malfunctioning, resetting power, etc. No weak solder joints, bad caps etc. Anyone ever figured this one out?

Also anyone using the probe? It would seem to take the fun out of things, but I have never seen one included in any listing, for sale, etc., and was curious if the system works better with it connected. The guy who gave me the enlarger said he never got a probe when it was new.

Also, I have been using Ilford VC setting with Ilford paper. Has anyone ever tried the other settings with better results on Ilford VC?

Anyone with questions about what’s in the manual I am happy to answer, but there is really not much in it.

Cheers

I talked to Kevin Brown at KHB in Ontario about my experience with these heads. Kevin does not like these heads.There's all manner of problems, software is bugged and no one has the original code to do anything. 3 lamps, in a closed loop system that depends on a funky photocell. Apparently Beseler replaced the original photocell under warranty. Since this Beseler ownership changed, so Beseler doesn't touch this old stuff. it's a shame these are fabulous heads when working.

And yes the buttons on the controller get gummed up and stick. I've had luck in taking the control keyboard pcb out and cleaning the switches under the plastic buttons. The key switches can be replaced.
No matter what one does the ghost in the machine can come back.

Same experience with the buttons. Also I traced all the points where the low voltage stuff controls the bulbs. Its pretty straight forward electronically so I suspect as you indicated the system gets nutty if voltages from the photocell or bulb resistance are off. Thankfully I can get it to work. I agree these are great when they work. Not having to mess with filters is worth all the nuttiness.

Does anyone know where to get replacement filters? What specific color are the blue and green?

The electronics are quite sensitive to electromagnetic surges. Don't have any electronic ballasts in the same building. Completely unplug the line if there's a lightning storm in the vicinity or power line utility work. If it goes schizophrenic, avoid using the enlarger a couple weeks. Part of the problem was that certain number of them received weak triacs. These are easily replaced. I can't recall the name of the company off the top of my head, but there is an electronic controller specialty company that can diagnose and repair them; but the fee with be relatively stiff.

But once one understands these, they can be configured to do excellent things with both color and variable contrast film. The only real difference is that the VC unit simply had the red filter replaced with a clear one. The narrow-band dichroic filter are "sandwich" style. Instead of using maximum density to allow only a specific wavelength through, they trim it off both sides. So each filter, R,G,and B, is actually a pair of filters. But there are also three filters in the feedback sensor, which sometimes needs gentle cleaning.

If you substituted custom-cut narrow-band single RGB dichroic filters in lieu of the original sandwich type, they'd be a lot denser, and you're printing times would be longer. Places like Hoya industrial division or Edmund Scientific Industrial division could supply that kind. You'd want true RGB color separation filters.

DREW WILEY said:

The electronics are quite sensitive to electromagnetic surges. Don't have any electronic ballasts in the same building. Completely unplug the line if there's a lightning storm in the vicinity or power line utility work. If it goes schizophrenic, avoid using the enlarger a couple weeks. Part of the problem was that certain number of them received weak triacs. These are easily replaced. I can't recall the name of the company off the top of my head, but there is an electronic controller specialty company that can diagnose and repair them; but the fee with be relatively stiff.

But once one understands these, they can be configured to do excellent things with both color and variable contrast film. The only real difference is that the VC unit simply had the red filter replaced with a clear one. The narrow-band dichroic filter are "sandwich" style. Instead of using maximum density to allow only a specific wavelength through, they trim it off both sides. So each filter, R,G,and B, is actually a pair of filters. But there are also three filters in the feedback sensor, which sometimes needs gentle cleaning.

If you substituted custom-cut narrow-band single RGB dichroic filters in lieu of the original sandwich type, they'd be a lot denser, and you're printing times would be longer. Places like Hoya industrial division or Edmund Scientific Industrial division could supply that kind. You'd want true RGB color separation filters.

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Thanks Drew.

I have a Kodak Static Eliminator setup. 5kV transformer, I don't use this anywhere near these heads. Just switching the static eliminator on and off can freak out the Beseler head.

The problem is, that if someone were to create a reasonable Faraday cage around the control units, and eliminate any cross-talk between the respective RGB channel wires, they'd need a far more bulky and heavy setup. You just can't cram all that stuff together in a tight space without some EMI cross-talk risk. I've made my own custom 8x10 pulsed additive head, and it's really huge and heavy; but I still get EMI problem even with that sometimes.

The last time I had an issue. it was when some fool trenching the main street hit the new underground high voltage electrical feed with his backhoe, and sent a voltage surge downline through the entire neighborhood. But nothing in my darkroom was ruined. I have a backup power supply; and even the previous one stopped its panicked muttering to itself after a couple of weeks. Simple surge devices and shape tamers do nothing preventative in this kind of EMI case, though they have other benefits.

The only way to truly tame this kind of issue introduces more long-term maintenance headaches that it solves. The three circuits in the Beseler U system are right around the maximum for that kind of electronics. But computerized sine-wave controls, as now used in rock concert light shows and big stage productions, and big high-rise "smart" energy-efficient lighting systems, can easily handle twenty or more solid state circuits at a time without EMI issues. The bad thing is that they're totally dependent on proprietary hardware and software, which as well all know, is exactly the kind of thing that goes obsolete quite fast, and has to be frequently updated, in this case, at especially high expense. So it's a lot easier just to learn a few rules to begin with, about what potentially makes your own enlarger control system go schizophrenic, and avoid those factors.

Anybody got a supplier and part number for a good bulb for the U45

Charles O'Connor said:

Anybody got a supplier and part number for a good bulb for the U45

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Takes an ESJ lamp, I would buy a generic one. If it is a Beseler part number a $15 lamp will cost $100.

I think it takes an EVW lamp, 82v 250w.

Todd Barlow said:

I think it takes an EVW lamp, 82v 250w.

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Thanks. Confirmed in manual. Purchased from Ushio here in CA @10.00 each.

Ok so I stupidly pulled the fan from the Universal 45 head without checking flow direction . Can someone please confirm if flow direction is left or right facing unit.

Fan operates counter clockwise.

The electronic feedback system can overheat if there isn't compete fan efficiency. I think it would be best to add a supplementary pull fan device taking hot air clear out of the room. After all, there are three 250W halogens all packed into a single tight space. I never like to operate these on a warm day. I might try putting a leakproof ice pack atop the head one of these days, just to see if there is less risk of a tantrum. Anytime engineers try to pack just too much into a relatively compact space, there's more complication. It isn't unique to this particular colorhead, but several expensive types with a surplus of bells n' whistles. It's been an especially cool season here, so I've only had one brief tantrum the past three months, with the loss of only a single sheet of paper.

Todd Barlow said:

Fan operates counter clockwise.
View attachment 341560

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Thank you!

DREW WILEY said:

The electronic feedback system can overheat if there isn't compete fan efficiency. I think it would be best to add a supplementary pull fan device taking hot air clear out of the room. After all, there are three 250W halogens all packed into a single tight space. I never like to operate these on a warm day. I might try putting a leakproof ice pack atop the head one of these days, just to see if there is less risk of a tantrum. Anytime engineers try to pack just too much into a relatively compact space, there's more complication. It isn't unique to this particular colorhead, but several expensive types with a surplus of bells n' whistles. It's been an especially cool season here, so I've only had one brief tantrum the past three months, with the loss of only a single sheet of paper.

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Hey Drew. You are correct that the head can get hot on a long exposure, but I do not see much in there that would cause the issues “tantrums“ I have read about. I have on the VC controller. Here is where I found solutions to mine going bonkers and have been running great for 2yrs on 36 hours week. No tantrums any longer.Look for ground issues and loose connections. Mostly found in the power unit. Tapping the unit with power on will sometimes trigger this type of issue. Take the cover off the power unit and tighten ground screws.

Resistance issues. 1. **Put in fresh bulbs. Be sure connector seated well. Check the cable. Not sure which wires do anything but a friend had a simple broken wire disabling everything. Not easy fix but manageable.

Broken solder joints. I have not seen any on controller or power units but I have heard of a color unit having a problem. Reflow if suspected. I have looked over about 5 units total.

The power unit is not likely to fail except for the cap. Look for bulging cap but again not likely given what is required of it. same with the output transistor. The board is simple and well made But is susceptible to loose wires and transient electrical noise with bad ground. I am running 10w safelight with no issues off the back. Best to just use as a switch to trigger a power box if running a bigger lamp.

Controllers. 1. Check cable continuity with power unit. Check LED with low dc power or small battery. Stuck buttons. Electrical there is not much fixable likely to go bad. Suppose ic could go but not likely. Look for signs of heat damage if a part is going. Bulging caps with age.

The dead units were all fixed with cables. One had a bad power switch, one had broken bulb socket.

To Drew. If you are having heat issues I would focus more on power unit first. Try to find bad electronics or load issues first else risk masking issue and a mess later. Digital controller next though i have not experienced this even warm. They do make those laptop fan pads which might help.

The lightbox to me looks adequately ventilated. Just pull the TOP cover to clean dust out. Do not remove the fan screws until you look at how fan is mounted. Its a weird setup with heavy metal brackets which fall free. I think they are light seal.

anyhow this is my experience. I have read the sensor in the diffusion chamber can cause issues But I have no idea what its values should be. In mine its present and clean. I have not put a meter on it because its fragile and no idea what to expect it to show.

good luck with the tantrums. If no help to you maybe someone else.

Charles - there are all kinds of components which can cause problems. For one thing, not all the original triacs were of good quality. But those are easy to replace. For another, EMI cross-talk can occur between the wiring and within the control boxes due to the cramped nature of all this. I have multiple power supplies and multiple control boxes, so can very quickly detect whether the problem is due to one of these or not, simply by switching them out.

These U colorheads were a compromise to begin with. Make em compact enough to fit on Beseler or other common 4X5 chassis, and with a self-contained minimal cooling fan, yet all within an unrealistically affordable price. Clever engineering, bad execution. Fully 50% of them failed in the first 2 months. After awhile, Beseler simply turned their back and refused to even honor the warranty. Then Beseler changed ownership, and the new ownership wants nothing to do with them. But with patience, the bugs can be worked out, or one can pay a premium to an electronics service provider. Word got around that if you have a working unit, stick with it, and don't sell it. But if someone is trying to sell off their components, avoid it unless you can test it first.

My own units have been heavily rebuilt and perform much more efficiently than the original design. But EMI is a constant threat. I had to avoid an entire month last year when electrical utilities were being re-routed underground; any sudden voltage surge would cause a turned-on unit to fritz out for a day or two. And EMI can jump ordinary surge protection devices.

I even cannibalized two whole U systems to design my own 8x10 additive head, along with special feedback monitoring which ZBE provided me. But ZBE's own high-output Starlight enlarger, the most sophisticated ever made, also proved to be the most temperamental colorhead ever marketed. I wisely avoided it. My own design is one of the best cooling ever, shy of a circulating water jacket, which has been used in certain giant UV enlargers of yesteryear.

Laptop fans are little toy things, and don't belong in an enlarger. One of my early enlargers was an old Durst color mural unit so bright and hot that it needed four pure silicone ducts attached to the colorhead, along with a 240V remote wall fan unit that took more juice than a true commercial table saw. That rig outright doubled my monthly utility bill. That's when I sold it and starting making my own design. And once you've got more than 3 solid-state light channels, EMI gets to be more and more a risk. I had 6 channels in one device. And it was only somewhat later that modern sine-wave lighting controls came into play in applications like multi-channel rock and stage concert shows, then complex architectural high-rise applications. But these are quite expensive and dependent on computer hardware and software that quickly goes obsolete - an even bigger headache! I won't further spell out my long-term solution; but that too involved a lot of rewiring, and bypassing finicky electronics. But oh - the sheer quality of color performance! - well worth it.

I was cleaning out the vents this morning. Flushed some air through the baffles and noticed the usual dust but also some silver metallic flakes. Small but uniform like glitter. is this paint? Anyone else seen this? Source of it?

Metallic flakes would imply dichroic filter spalling off either the bulb reflectors or the colored dichroic filters themselves, most often due to overheating. Bulbs are easy to replace. You want to open the top and inspect all of that, and gently vacuum things out. Once in awhile, bulb sockets might need replacing too, if corrosion is occurring between those and the bulb pins, which could also potentially cause some metallic-looking dust.

Did anyone ever find a OEM source for the filters in the universal 45? Or know specifications for the sandwich of filters as Drew describes. Looking for new set as my green is a bit heat damaged.

DREW WILEY said:

Metallic flakes would imply dichroic filter spalling off either the bulb reflectors or the colored dichroic filters themselves, most often due to overheating. Bulbs are easy to replace. You want to open the top and inspect all of that, and gently vacuum things out. Once in awhile, bulb sockets might need replacing too, if corrosion is occurring between those and the bulb pins, which could also potentially cause some metallic-looking dust.

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It was the bulb reflector disintegrating. Specifically the focus lamp. Thx

I have been tracing the wiring between the head and the power unit. I have the VC controller. Does anyone know how the op amps are used in the circuit? Are they just comparators to the sensors in the head? Do they control the brightness on the negative input through the resistor? I see another post where a op amp was changed out to fix blue light intensity issue so thats a clue, but not easy to see on scope. I have the op amp spec but its capable of many uses.