BESELER 23c II exposure hiccup

[Al--Pacino]

I suspect it's internal to the head. Sounds like your head has two power cords, both designed to plug into 110V 60 Hz. One supplies power to the enlarger main power switch, when you switch the main switch the cooling fan comes on.

The other 110V cord plugs into the timer or any sort of manual switch that controls the lamp.

82V is an internal power supply.

Every 45S colorhead I've had has had a similar failure of a Vactrol opto-isolator. I've fixed 4 of these, I just did what a Beseler employee told me to do. The Vactrol looks like a little soup can, has 4 leads. I'm not a electronic type, just did as told.

This is where I would start.

This is correct, from my Dicho Duel-S there is a grey power cable, and a black power cable.
The Black is labeled for timer, the grey labeled for power.

I have the black, for timer, supplied to my timer.
The grey is to the outlet-- same outlet as the timer, which is plugged into the head.

I can supply images tomorrow for y'all who would like to better understand.

Appreciate the comment about acting as you're told. I intend to do the same. I just am waiting to hear from those who know better than I about where to go about solving my problem.

I'm going to assume this will require soldering, if I go the route of replacing the soup can?

 

[MattKing]

That light source head looks to be of the same vintage as the dichro colour heads for the Beseler 67 series after they switched from needing separate power supplies to having the power supply built in - so this could be something similar.
That certainly applies to the current dichro head.

 

[mshchem]

This is correct, from my Dicho Duel-S there is a grey power cable, and a black power cable.
The Black is labeled for timer, the grey labeled for power.

I have the black, for timer, supplied to my timer.
The grey is to the outlet-- same outlet as the timer, which is plugged into the head.

I can supply images tomorrow for y'all who would like to better understand.

Appreciate the comment about acting as you're told. I intend to do the same. I just am waiting to hear from those who know better than I about where to go about solving my problem.

I'm going to assume this will require soldering, if I go the route of replacing the soup can?

Yes, a soldering iron and some disassembly. Problem will be finding a substitute part. There's a lot of discussion here about this in the 4x5 heads.

Again I've never seen the insides of the 23c heads.

 

[Ian C]

Regarding post #18:

The male “6-Pin Connector” is only found on the cable end of the DGA and the Dual Dichro heads. The female socket is on the 24 VAC power supplies. It’s a Cinch Jones connector that carries 120 VAC current from the external power supply to the head to power the cooling fan and panel illuminators. It also carries the 24 VAC current from the external power supply to the lamp. It has nothing to do with the OP’s Dual Dichro-S.

In the following link to the Dual Dichro manual, page 7 figure 24 shows the Standard 24 VAC power supply. Figure 25 shows the 24 VAC Stabilized Power Supply.

http://www.jollinger.com/photo/cam-coll/manuals/enlargers/beseler/Beseler_DualDichro23_head.pdf

The Dual Dichro-S uses a simple half-wave diode and power resister power supply, small and compact, built into the lamp head. This results in approximately 82 volts (pulsing DC) to the lamp. Any time you encounter an enlarger, projector, or any device that uses an 82-volt quartz-halogen lamp, you can assume that it’s powered by diode-and-resistor power supply. They're cheap to build and rarely fail. If they do, you can unsolder the bad part and replace it. It’s only when a more complex voltage stabilizing circuit is incorporated into the design that it becomes potentially unstable with aging.

The power supply of the Dual Dichro-S (disregarding the voltage-stabilizing circuit) looks like the first diagram in the following link. You must click onto "Continue Reading" to see the full diagram.

https://www.quora.com/What-is-half-wave-power-supply

The Dual Dichro-S power supply use a voltage-stabilizing circuit employing a Vactrol and other electronic components. The Vactrol tends to fail as it ages. That can make the unit unusable. Essentially the same voltage stabilizing circuit is found in the 24-volt Stabilized Power Supply for the DGA and Dual Dichro (incompatible with the Dual Dichro-S head). Most owners don’t have the resources to diagnose the problem, obtain the parts, and make the necessary repairs.

Vactrol (Resistive opto-isolator):

https://en.wikipedia.org/wiki/Resistive_opto-isolator

Some Vactrol related posts:

https://www.photrio.com/forum/threads/beseler-lamp-delay-for-printing.3703/page-2

https://www.photrio.com/forum/threads/beseler-dual-dichro-s-23-schematic.27131/

Unless you have electronics experience and can locate the necessary replacement parts, you can resolve the problem by looking for either a DGA or Dual Dichro head to replace the faulty Dual Dichro-S head. Both the DGA and Dual Dichro heads require a 120 VAC to 24 VAC external power supply. I strongly advise avoiding the Stabilized Power Supply as it is likely to have the same problem as your Dual Dichro-S. The dichroic heads are for either B&W or color work.

If you intend on doing B&W enlarging only, then it will be much easier to obtain a standard lamp holder. Simply unfasten the dichroic head and lift it straight up and off of the lamp housing, set the lamp holder in place and snug the fastening knob.

The older lamp holders use the small, spherical-envelope PH-111 bayonet mount lamp. The newer version uses the larger PH-140 E26 screw base lamp. You can use either version. I prefer the later version with the PH-140 lamp. Both are 75-watt opal photo lamps and are cheap and plentiful in 2025. It’s economical to buy them in 6-lamp packs:

https://www.bhphotovideo.com/c/prod...osram_11624p_ph111a_75w_125v_lamp_6_pack.html

https://www.bhphotovideo.com/c/prod..._osram_11625p_ph140_75w_120v_lamp_6_pack.html

PH-140 lamp holder (the type I prefer)

https://www.ebay.com/itm/267056582961?_skw=Beseler+23C+lamp+head&itmmeta=01JMCH6F7M32JVAV0S932Z45K2&hash=item3e2dd01131:g:aQ0AAOSwNoJnLWuT&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1eAB9pDMOxzIfFpn7Ltqpj5JBL34vlvfBxXaL2oli9NoX2k1hp5sUb38nApBAG38sK14Zps8US5skj9Cr6gklC+sIJNZljgjfdBzghk1QdaFgx02XVug2u+qXQ3it8zH8WCkHdCxZ40dQVv0apRgOZdKciVJGRM76K36c434rRr1aW9qRrw6uKOEgMqc42V8jqz50ML0nGV61G1iSNo2gYyYR3KClPbB6UEYebXOav/6t9gKFYvSAQKLOyPKEvCxN9LtFBu6mhOQSa2+MM/dtfqpiKqciHXnL9gBua/2Fdxug==|tkp:Bk9SR_zzmZGjZQ

PH-111 lamp holder

https://www.ebay.com/itm/326387924685?_skw=Beseler+23C+lamp+head&itmmeta=01JMCH6F7MQG0A5DVRK39DSACY&hash=item4bfe3c7ecd:g:UhYAAOSwlb1nYMCE&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1diGExKQk74hzFxmFmgM3JjIvA9PXU0xJ5qVD+BeYqFpeFVyHvO5Y8torRtBEswV1UWYtFHvaBa67LJZ0feoRdypkxRnA2LnWMBzyCegEcOZJBpUWJ60OlaHwKjmdFsHexBI+RUqzSJ628o7BFWySYc9y0GogdERAbwJuUjNF67u9xAmgdXMP8Vjhqfxf9t1jPnWnS8ePA8atK5ZqgkyLC73fgiUdN3eAzUrvkJzcQ7clyRMnx0FXZFmKnq7TOgtfiApPbo4+6nYYLXzm1/3v/qyAnUnlUb0F9FbVi3AVxxQg==|tkp:Bk9SR_zzmZGjZQ

 

[mshchem]

Regarding post #18:

The male “6-Pin Connector” is only found on the cable end of the DGA and the Dual Dichro heads. The female socket is on the 24 VAC power supplies. It’s a Cinch Jones connector that carries 120 VAC current from the external power supply to the head to power the cooling fan and panel illuminators. It also carries the 24 VAC current from the external power supply to the lamp. It has nothing to do with the OP’s Dual Dichro-S.

In the following link to the Dual Dichro manual, page 7 figure 24 shows the Standard 24 VAC power supply. Figure 25 shows the 24 VAC Stabilized Power Supply.

http://www.jollinger.com/photo/cam-coll/manuals/enlargers/beseler/Beseler_DualDichro23_head.pdf

The Dual Dichro-S uses a simple half-wave diode and power resister power supply, small and compact, built into the lamp head. This results in approximately 82 volts (pulsing DC) to the lamp. Any time you encounter an enlarger, projector, or any device that uses an 82-volt quartz-halogen lamp, you can assume that it’s powered by diode-and-resistor power supply. They're cheap to build and rarely fail. If they do, you can unsolder the bad part and replace it. It’s only when a more complex voltage stabilizing circuit is incorporated into the design that it becomes potentially unstable with aging.

The power supply of the Dual Dichro-S (disregarding the voltage-stabilizing circuit) looks like the first diagram in the following link. You must click onto "Continue Reading" to see the full diagram.

https://www.quora.com/What-is-half-wave-power-supply

The Dual Dichro-S power supply use a voltage-stabilizing circuit employing a Vactrol and other electronic components. The Vactrol tends to fail as it ages. That can make the unit unusable. Essentially the same voltage stabilizing circuit is found in the 24-volt Stabilized Power Supply for the DGA and Dual Dichro (incompatible with the Dual Dichro-S head). Most owners don’t have the resources to diagnose the problem, obtain the parts, and make the necessary repairs.

Vactrol (Resistive opto-isolator):

https://en.wikipedia.org/wiki/Resistive_opto-isolator

Some Vactrol related posts:

https://www.photrio.com/forum/threads/beseler-lamp-delay-for-printing.3703/page-2

https://www.photrio.com/forum/threads/beseler-dual-dichro-s-23-schematic.27131/

Unless you have electronics experience and can locate the necessary replacement parts, you can resolve the problem by looking for either a DGA or Dual Dichro head to replace the faulty Dual Dichro-S head. Both the DGA and Dual Dichro heads require a 120 VAC to 24 VAC external power supply. I strongly advise avoiding the Stabilized Power Supply as it is likely to have the same problem as your Dual Dichro-S. The dichroic heads are for either B&W or color work.

If you intend on doing B&W enlarging only, then it will be much easier to simply obtain a standard lamp holder. Simply unfasten the dichroic head and lift it straight up and off of the lamp housing, set the lamp holder in place and snug the fastening knob.

The older lamp holders use the small, spherical-envelope PH-111 bayonet mount lamp. The newer version uses the larger PH-140 E26 screw base lamp. You can use either version. I prefer the later version with the PH-140 lamp. Both are 75-watt opal photo lamps and are cheap and plentiful in 2025. It’s economical to buy them in 6-lamp packs:

https://www.bhphotovideo.com/c/prod...osram_11624p_ph111a_75w_125v_lamp_6_pack.html

https://www.bhphotovideo.com/c/prod..._osram_11625p_ph140_75w_120v_lamp_6_pack.html

PH-140 lamp holder (the type I prefer)

https://www.ebay.com/itm/267056582961?_skw=Beseler+23C+lamp+head&itmmeta=01JMCH6F7M32JVAV0S932Z45K2&hash=item3e2dd01131:g:aQ0AAOSwNoJnLWuT&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1eAB9pDMOxzIfFpn7Ltqpj5JBL34vlvfBxXaL2oli9NoX2k1hp5sUb38nApBAG38sK14Zps8US5skj9Cr6gklC+sIJNZljgjfdBzghk1QdaFgx02XVug2u+qXQ3it8zH8WCkHdCxZ40dQVv0apRgOZdKciVJGRM76K36c434rRr1aW9qRrw6uKOEgMqc42V8jqz50ML0nGV61G1iSNo2gYyYR3KClPbB6UEYebXOav/6t9gKFYvSAQKLOyPKEvCxN9LtFBu6mhOQSa2+MM/dtfqpiKqciHXnL9gBua/2Fdxug==|tkp:Bk9SR_zzmZGjZQ

PH-111 lamp holder

https://www.ebay.com/itm/326387924685?_skw=Beseler+23C+lamp+head&itmmeta=01JMCH6F7MQG0A5DVRK39DSACY&hash=item4bfe3c7ecd:g:UhYAAOSwlb1nYMCE&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1diGExKQk74hzFxmFmgM3JjIvA9PXU0xJ5qVD+BeYqFpeFVyHvO5Y8torRtBEswV1UWYtFHvaBa67LJZ0feoRdypkxRnA2LnWMBzyCegEcOZJBpUWJ60OlaHwKjmdFsHexBI+RUqzSJ628o7BFWySYc9y0GogdERAbwJuUjNF67u9xAmgdXMP8Vjhqfxf9t1jPnWnS8ePA8atK5ZqgkyLC73fgiUdN3eAzUrvkJzcQ7clyRMnx0FXZFmKnq7TOgtfiApPbo4+6nYYLXzm1/3v/qyAnUnlUb0F9FbVi3AVxxQg==|tkp:Bk9SR_zzmZGjZQ

Yep, the most reliable thing is the regular condenser head with a tungsten lamp, foolproof. Use acetate CC filters for color, VC acetate filters for black and white. It's a snap once you get the right filter pack.

The 23C III dichroic heads are modern and very reliable available for color or VC. This is what I would look for.

 

[mshchem]

BESELER 23C SERIES III | eBay

BESELER 23C SERIES III. Condition is Used. Shipped with USPS Ground Advantage.

www.ebay.com

 

[Al--Pacino]

Regarding post #18...

Thank you, mate. This is the perfect information for me going forward. Cheers to you.

I think for the time being I'll switch over to my Minolta II enlarger while I source a new head, vactrol, or just replace it with incandescent, since I pretty much only use it for BW and 4x5.

Thank you all for this wild journey. Hope to update you all in the coming future regarding my repair.

 

[paul ron]

im not sure if your head is the same one with the vactrol problem... anyway this was covered here...

Timer/Enlarger...delay with activating light

Beseler 45. Three different timers. I have tried to find a pattern, but i do not see one. Does not seem to matter if the enlarger is cold or hot...moving/pulling the power cord from timer to enlarger has no effect...pushing the timer button Hard/Easy/Slow/Fast makes no difference. What is...

www.photrio.com