Going to check out a Chromega D Dichroic II (what to look for)

[arespencer]

Regarding the question in post #24,

“Have any of you seen or heard about this issue with the times being wildly off and, in some cases, just wouldn't turn off?”

Yes. That perfectly describes the behavior of an ailing Chromegatrol. The switch has nothing to do with the timing problem.

Chromegatrols become unreliable as the components age. The timing is controlled by the constant charge/discharge rate of the 5 timing capacitors: C1, C2, C3, C4, and C5.

The large C6 Capacitor (in the aluminum can) is connected to a solenoid wound about the transformer core. It’s part of the voltage stabilizing tank circuit and has nothing to do with timing. It almost never needs replacing.

Referring to the schematic, C1 and C2 are electrolytic capacitors. These are liable to go bad as they age (changes to the electrolyte). You can test a capacitor with a multimeter. Unfortunately, capacitors must be unsoldered from the circuit to test them. I’d pay particular attention to C2. It’s a 300μF 50 VDC electrolytic capacitor.

If you’ve removed a capacitor from the circuit to test it, you might as well replace it with a new one. Electrolytic capacitors have a polarization that is marked on the body. That polarity must be maintained when you replace it. You can see this in the schematic. Note the + sign adjacent to the C1 and C2 capacitor designations on the schematic. Capacitors C3, C4, C5, and C6 are unpolarized.

Of course, there are other components that might have become defective: resistors, capacitors, diodes, and the LM322M timer IC (available on eBay).

https://www.ebay.com/sch/i.html?_nkw=LM322M+timer+IC+&_sacat=0&_from=R40&_trksid=p4624852.m570.l1313

To avoid the potential problems with an aging Chromegatrol, instead try to find the Standard Power Supply 412-021. It’s simply a 120-volt to 22.5V step-down transformer. These are simple and rarely give trouble. The ON-OFF switch is the only moving part. You can use the Standard Power Supply with any timer with at least a 400-watt capacity.

http://store.khbphotografix.com/120V-Power-Supply-for-Super-Chromega-D-and-E-Colorheads.html

If you’re patient, you can find one used at a reasonable price on eBay. The Solid-State Voltage Stabilizer 404-841, or a line stabilizer, is needed for color printing. It’s unnecessary for B&W printing.

http://store.khbphotografix.com/Voltage-Stabilizer-for-Chromega-D-and-E-Dichroic-Enlargers.html

Thankyou so much. So this one is basically not working either but working better than my last one lol. If im mostly color printing I need both the Standard Power Supply and the Voltage Stabilizer and then a timer as well? That price adds up and I found a refurbished chromegatrol on KHB for under $700. I'm wondering if I should just suck it up and buy that one?

I did have 1 questions though for a work around. Is there any reason why exposing my prints "manually" wouldn't work. By manually I mean turning on the focus switch and then counting out the seconds for my exposure. I would try to always print around 15-20 seconds or more so that my timing be off by a second wouldn't have too big of an affect. Is there any reason why this wouldn't work or give me relatively accurate results. Does the power/light fluctuate when turned on in focus mode since its running a different power supplied to the enlarger?

 

[MattKing]

A separate multi-purpose power conditioner between the wall and a timer will fulfill the function of the voltage stabilizer, and as they are useful in the computer world, they are easily found.
And for colour printing, where the exposure times can be quite short, you will want a timer.
I rely on the timer heavily for black and white printing as well.