View Full Version : Zone VI Compensating Enlarging Metronome "TikTok"

Luther Hert
15-Oct-2014, 22:25
I have a Zone VI Compensating Enlarging Timer with L702 Photodiode Assembly, a Zone VI foot switch, and a ZONE VI Variable Contrast Cold Light Head and controller. I do not have a Zone VI Metronome. What else might I find to substitute for the Zone VI Metronome, since none are available? Is there a way to configure the Zone VI Enlarger timer to cut off the light, when the enlarging time is finished? How may I solve these problems? I have found one post regarding the issue and it is about moving a lens cap over the lens. I need a more practical means that cuts the enlarger light off automatically, when the time is up. I would hope this would also allow me to use the Zone VI enlarging timer.

Doremus Scudder
16-Oct-2014, 02:27
A Zone VI compensating timer will start and stop the enlarger light if you have it connected correctly; that is its intended function. Check to make sure you have the enlarger lamp circuit plugged into the proper receptacle on the timer. You should be able to start the exposure with the footswitch.



Luther Hert
16-Oct-2014, 10:59

Thank you for your quick reply. I checked the enlarge lamp circuit. From the light head timer receptacle, I have an electrical cord running to the lamp receptacle located on the Zone VI Compensating timer. Another electrical cord runs from the power inlet to the AC electrical circuit. The telephone type cord is plugged into the telephone type jack at the rear of the control box. The three pronged plug for the light sensor coming from the compensating timer is plugged into timer inlet at the top of the light head.

When the power is turned on the light head responds immediately and requires no warm up. It was 58 degrees here this morning. The brightness controls, focus, print, and lamp controls on the control box work. Both lights work in the light head. The light head checks okay.

The Compensating enlarger timer seems to be problematic. It does not emit any sound that it is operating, the timer dials do not work in conjunction with the light head. When I set the dial to what I believe is one second print time, the light comes on and stays on. I cannot use the foot switch or the red timer switch to cut off the light. Perhaps, it is something that I am doing wrong, but I think that seconds would count off on the timer so that I would know when the printing time is up and I should ber able to stop it without hitting the power switch on the timer. I lost on this one. I think the compensating enlarger timer is bad.


neil poulsen
16-Oct-2014, 12:34
I don't see your sensor in the photo. So, I can't compare it to my own. I think the problem is that the sensor is not connected to the timer, or that you don't have a correct sensor. The timer could be fine; you may be experiencing problems with the sensor.

Sensor and head connected to my compensating timer, and all works well. Sensor disconnected w/head connected, and I experience the same that you experienced. Light stays on, and there's no indication (like the beep) that time is advancing on the timer.

To add a little detail, the dimmer the light, the slower time advances on the timer. That's why it's a compensating timer. If there's no light, time doesn't advance at all. (Which is what I think you're experiencing.) An improperly connected sensor could signal the timer that there's no light.

Could your sensor be intended for a Metrolux timer, the other popular compensating timer? If so, there needs to be an adapter to connect a Metrolux sensor to a Zone VI timer.

Peter Lewin
16-Oct-2014, 12:36
Luther: I'm having a little trouble determining from your description whether all the cords are going to the correct places (it sounds as if they are). Here is the text of the ZoneVI instructions for the compensating enlarging timer:
"1. Plug your enlarger's lamp head into the outlet labeled 'lamp' on the timer. Plug the cold light's "thermo" (heater) cord into a normal power outlet. (wall outlet.) Unplug after printing.
2. Plug the timer into a grounded (3-wire) wall outlet.
3. Plug the cable labelled 'cell' into the other connector on your ZoneVI Cold Light Head. If you are using some other lamp head, you must install a ZoneVI L702 photocell.
4. Allow the lamp head to warm up to normal operating temperature. You can sped things up by running the lamphead (use 'focus', with 'lamp' set to maximum) for a few minutes. Then set the timer for a 10-second exposure, set the 'lamp' and 'sound' controls to maximum, set 'dry down' to 0, and press 'start' or the footswitch. The lamp head should light, and you will hear metronome beeps. Now turn the small blue calibration adjustment (on the top edge of the timer, just above the 'C' in the word 'Compensating') until the beeps are approximately 1 second apart. Once you have set this adjustment, leave it alone."

Re-reading your note, it sounds as if you have the switch on the lower right side of your timer set to "focus" so as soon as you turn the power switch to "on" the cold light turns on and stays on. Make sure the focus switch is flipped to the opposite side, which will let the timer circuit function.

Hopefully your timer is fine, and leaving the "focus" switch set to the "focus" setting is causing your "symptoms," because what you describe matches the focus setting perfectly!

Edit: I see that Neil Poulsen posted a response while I was typing, I guess there are several things which would cause the symptoms you describe.

Keith Pitman
16-Oct-2014, 17:52
It's not clear (to me, at least) from your last post whether you have both power cables from the cold light head plugged in. As Peter describes, one should go to a power source that is on all the time while you are working, and the other goes to the timer which switches the light on and off. If you have both power cables, make sure the connections are not reversed. If none of the advice here seems to help, I suggest you post pictures of your whole set-up showing all the connections. The picture of the VC control and the footswitch isn't helpful.

Luther Hert
16-Oct-2014, 19:36
The sensor is built into the Variable Contrast Zone VI light heads. Attached to this posting are pictures of the top of the light head, the controller box, and compensating timer. There are two electrical outlets in the top of the light head. The outlet marked timer attaches to the male electrical plug on the left side of the compensating enlarger timer. The other outlet attaches to an ac electrical wall socket or other source. The other plug attaches to a sensor cord from the compensating timer into the third outlet located on the top of the light head. This is where the sensor is installed over the lamps. That is why you cannot see the sensor, but you do see the cords and connections to the sensor, which is located inside of the light head.

Two other persons looked at this today, the controller box, and the compensating timer today, and the light head. They are more experienced with Zone VI equipment than I am. They determined that it is an issue with the Compensating Enlarger Timer. The light head and its controller box are performing as they should. The Compensating enlarger timer does not make any sound (count down noise per second and so forth), it has a noise controller to turn up and or lower this sound, but there is no sound emanating from the timer. The dials that set the time do not seem to be working either.

About your theory with the sensor, some of that may well be true. The cable from the compensating enlarger timer could be loose inside the timer box, but that does not explain why the timer does not do a count down and will not turn on and off with the red start button or a foot switch. The foot switch is a brand new Zone VI foot switch. The problems seem to be isolated to the compensating enlarger timer. There is a person in a nearby town, who has fixed Zone Vi compensating timers before. If the person, from whom I bought it from will work with me, I will take the timer to this person for repair. I am attaching better pictures of the timer, controller, and the light head, which indicate where the wires attach. I thank everyone for their responses. I am leaving this open, in case, I can successfully get it repaired. I will share the information here.

Keith Pitman
17-Oct-2014, 06:33
I think Neil is on the right track. I remember now that the Zone VI timer would not work unless it was plugged in to the enlarger head. I would make sure the sensor cable plug making proper contact with the socket in the enlarger head.

Luther Hert
17-Oct-2014, 07:58
Neil is on the right track. I just got a message from the seller, who said that the diode may not be working or may be wired backwards. He suggest that I open the connector and reverse the diode wires. I suspected the diode. I hope it is wired backwards because obtaining another diode may be very difficult. Later today, I will try reversing the diode wires. I will keep all posted, so this remains documented for others. Thank you.

17-Oct-2014, 08:15
You do have BOTH Focus setting buttons off, right?

neil poulsen
17-Oct-2014, 10:31
I tested this on my own setup. I have a Zone VI compensating timer that's connected to a Beseler 45S head in which I installed a sensor. If I disconnect the sensor, my timer behaves as your timer behaves.

Luther Hert
17-Oct-2014, 12:30
When the last pictures were taken, the Compensating Enlarger Timer, Zone VI Control Box, and the Zone IV VC Light Head were separated, in order for me to take pictures of them. When the items were assembled on the Beseler 45, their electrical circuits were properly attached. The light head and control box worked as they should. The compensating enlarger timer failed work properly. It will not count down or produce any sound that shows it is working.

I just finished inspecting the male 3 prong timing plug socket that is inserted in the top of the light head to connect with the light diode located inside the light head. The wiring was secure and it does not appear that anyone has ever modified it. This is easy to get too. This is where this currently stands.

Keith Pitman
17-Oct-2014, 12:36
You could test the head separately by plugging the cord that normally goes into the timer into a wall outlet. If it goes on and then off when you unplug it, you have confirmed that the issue is with the timer or the timer/enlarger connection.

Luther Hert
17-Oct-2014, 12:40
Keith and Neil, I am still working on Neil's theory about the socket connection in the light head. As I just mentioned the prior response, I just finished inspecting the male 3 prong timing plug socket that is inserted in the top of the light head to connect with the light diode located inside the light head. The wiring was secure and it does not appear that anyone has ever modified it. This is easy to get too.

The next step seems to be to the internal timer connection of the 3 prong plug. If that appears secure and nothing is loose. I will have to decide whether or not to try and inspect the wiring attached to the diode inside the light head (I may not want to tackle that as I may not have the proper hex wrenches to get inside of the light head.)

Luther Hert
17-Oct-2014, 12:45
Keith, I plugged the head in and tested it with the Zone VI Control Box, by doing the test you just recommended. That is why I think the problem is with the Compensating enlarger timer as it is the only piece of the puzzle that is not working. I am taking a further look at the timer now. If I find nothing there, I will try to visually inspect the light head diode.

Doremus Scudder
18-Oct-2014, 01:31

It sounds as if you may have a faulty sensor. Even if the wiring is in good order, a faulty sensor (i.e., not sending and current) would give you the results you are experiencing. In that case, you'd have to replace it. Maybe someone here knows the a source for the proper replacement.



Luther Hert
18-Oct-2014, 07:49

It sounds as if you may have a faulty sensor. Even if the wiring is in good order, a faulty sensor (i.e., not sending and current) would give you the results you are experiencing. In that case, you'd have to replace it. Maybe someone here knows the a source for the proper replacement.




I thank all of you for staying with me through this ordeal. Are you stating the light head may have a faulty sensor or would you surmise that the faulty sensor would be on the Compensating Enlarger side?

When I bought the compensating enlarger timer, it came with an extra L702 Photocell & Receptacle (light sensor). I completely disconnected the light head from the compensating timer. I checked the compensating enlarger timer's wiring of the light sensor receptacle that normally attaches to the light head. The wiring was intact, however, because I have no schematic, I do not know whether or not the wiring may have been reversed at an earlier date.

Assuming that the wiring was correctly attached, I plugged the extra light sensor into the compensating timer's light sensor receptacle, I set the timer's right hand side timer dial to 5, turned the sound button up to max, plugged the timer into an ac outlet, turned on the timer, and shined a flash light on to the fresh light sensor. The timer emitted a whistling type sound, but did not do a count down, so I assume something is wrong with the timer's sound count down mechanism that prevents an audible count down. Before I did this experiment, no sound whatsoever emitted from the timer, when it was connected to the light head.

Next, I re-assembled the compensating enlarger timer, light head, and the light head's controller box. I tilted the light head sideways enough to observe the light coming from the light head. This time, I set the timer's right hand side timer dial to 1, turned the sound button up to max, plugged the timer into an ac outlet, turned on the light head, then the timer. The timer emitted no sound. However, I used the stop watch on my cell phone to time the time from when the light came through the light head to when it cut off. The light did cut off, after approximately one minute. So, there is some communication between the light cell in the light head and the enlarging timer.

The timer still will not allow me to press the red start/stop button or use the foot switch to stop the timer. It just keeps going until the time is up. In this case, it is one minute. So there is no way to interrupt the timer, unless you use one of the main cut off switches located on the right hand side of the timer or the right hand side of the light head. Also, it is impossible to set the timer incrementally, by 10ths of a second or even by seconds, or any amount of time less than a minute. This is a crucial problem when making an exposure. The fresh new light sensor did not remedy the incremental timing issue. There is communication between the light head sensor in the enlarger head and the enlarger timer, because the light grid is shutting off at the time set. The problem is that the time canot be set incrementally in units of less than a minute.

There are two observed problems with the timer, the inability to properly emit a count down sound, and the inability to properly set the length of time on the timer. After two days, I am giving up and returning the enlarging timer. If someone knows where I can find and buy an extra L702 Photocell & light Receptacle (light sensor), I would be thankful as I still have an Aristo VCL4500 Light Head that I wish to use with a compensating enlarger timer and I will need the light cell.

The current extra light cell that I have came with the faulty compensating enlarger and the seller may want to keep that one. So if any one knows where I may find a light cell, please contact me. I thank everyone for coming forth to help. This forum has some really kind and helpful members. I hope I may offer someone else as much help in the future.



Eric Woodbury
18-Oct-2014, 16:31

Let's start with the extra light sensor. Sounds as though you got a continuous tone. If so, it could be that the flashlight was so bright and the timer so out of calibration that all the beeps ran together as one. You should try doing a calibration. Do you have instructions? Neil P posted some here:


As far as getting a new photo sensor, this is doable too. Not much to this circuit. You will need a photo diode. You'd like to find one about the same area as what was intended. Zone VI used 2 x 2 mm sensors last time I saw one, but you can check by looking at your sensor. There should be a small shiny square in there (if it is like the one I saw). It might have a light blue filter over it. See what size it is. Either 2 x 2 mm (0.08 x 0.08 inches) or half that would be most common. You don't need to be too accurate. Here's an example, albeit a different shape than the one you have. The one you have is probably from Hamamatsu.

Let's see what happens with this info first.