When a cue is read, the "stepper" goes, "Chicka - chicka - chicka.....", all the way down the board and just keeps going. It keeps going 'round and 'round and never stops.

We changed out all the relays and no effect. Any ideas?

I had a very similar problem with the stepper- turned out to be that transistor for the #1 projector that is mounted at the bottom.
 

However, one of the last ones I saw was in Huntsville, Alabama in a 70mm house in late '60's. It worked most of the time. Maybe the newer models were ok, but I was not impressed with what I saw in the older models. The projectionist was complaining about it popping diodes on a regular basis.

And, from what Gordon is saying, it just seems like too many things can go wrong with them.

------------------
John Eickhof President, Chief Slave
Northwest Theatre Equipment Co., Inc.
P.O.Box 258
Wendell, ID. 83355-0258
208-536-5489
email: jeickhof@nteequip.com
 

Unfortunately these days howerver, more and more, the job of programming is being left to staff who have neither the training nor inclination to put of a good presentation. They are usually satisfied if they manage to "get through a show" without too many refunds.

At a couple of theatres I visited, for example, they had the sound switching to Dolby 04 simultaneous with the projector motor starting, giving the audience the pleasure of hearing the leader and sync "beep" as it came up to speed.

Re: your intemittent problem with this automation, relay "C" as i recall, is responisible for the auto stepping function. If a shorted diode in row 15 is present, the thing will step forever.

Row 15, by the way is a good way of checking diodes. Simply fill up the row with diodes to be checked and pulse the board. It should continue merrily on its way around the 48 steps, continuoulsy. It it does, all diodes are at least, conducting. Remove one diode and the stepper should stop when it reaches this line. (Now you know that none of the diodes is shorted, either.) If it continues on, one of your diodes is shorted. (I have replaced the diode elements too, with 1N4004 diodes at a cost of about 14 cents each).

In one of the first installations of these boards, in Belleville Ontario, back in '68, the installation electrician failed to provide protection for the circuitry before drilling holes for elecrtical conduit into the top of the automation, resulting in many metal particles throughout the automation. This caused mysterious cues to appear during the show for years after.

Gordon brings up a good point about the blue Crouzet sensors. They are normally closed, meaning that the R-10 relay is normally energized until they see a pulse. They temporarily de-energize and the normally-closed contacts cause the board to pulse. If the sensor is going (good luck finding a new crouzet), or the relay contacts are badly worn, this will cause the stepping you describe.

The sensor can be changed to a normally open type, provided you change the pin connections on the R-10 to normally open. An addittional advantage of this is that the board will not step every time you turn it on.

Let me know if you need any crouzet sensors.
 

The Philips/Norelco/Kinoton version was similar and was acknowedged as one of the best automations made.

Today the CA21 made by Pennywise and sold by Christie and Kinoton is essentially an electronic version of the old relay matrix boards of the Cinemation era.

The advantage of these matrix units is that you can see what has happened i.e. follow the trail and see what is coming up next.

For a photo see page 135 of your SMPTE Motion Picture Projection and Theatre Presentation Manual, 1969 version!

David

The guy here in the UK who designed and built these units was Bernard Bentley. I have no idea if he is still in circulation. I have aquired some drawings of the MkIV, and with the help of a colleague who's a little older than me, it looks like the problem is either the cue detector itself, or possibly either a transistor or capacitor in the pulse detection circuity. Now the trannies are germanium and therefore obsolete, there is however an equivalent, but that's getting rare too. I'll post my results, good bad or indifferent.
 

I was wondering if anyone knew if he ever did develop a solid-state version.

As an example of the fine workmanship of these units, all wiring was terminated with colour-coded markers, using EIA colour codes. (Brown-red, for example indicated 12). Made it a whole lot easier to trace without a schematic.

Personally I've never actually used one of these units, I had the Mk10T at one place I worked and that was an ok bit of kit, it has to be said that for it's day it's a good solid old machine. There is one cinema in town (not one of my services, but I know the guys there) that is still using the twin pegboard unit. They have a set of contacts set up to switch on the coffee maker at the end of the show! Try doing that with a CNA or a Vectra!
 

I got had to get back on my route because I was getting so behind on my schedule. I've been putting in over 1,500 miles a week lately. Most of it was for emergency calls.
 

I bought a 0-15 min timer (just like the 0-60 min timer that came with the unit.) I hooked it to a function line to start it. When it timed out, it would step the unit to bring down the house lights, and select "C" on the CP200 (which was set to the feature format.)

We didn't have very many diode pins, so could only program a few shows; then we had to step the thing back to the top. I got tired of doing this, so wired the stepper to automatically step from line 25 to the top.

As I said; you had to spend some time understanding it, but it was worth it.