Cinerama Servo amplifier

[Bill Ryan]

[QUOTE=Mark Gulbrandsen;I'm still puzzled why you would want to put these back to the Rube Goldberg style system that was obviously abandoned in later-simplified versions of the system??? Have you contacted John Sittig yet?
[/QUOTE]

Hi Mark,
I don’t know what you mean by Rube Goldberg
system. All I am trying to do is using the original
system that was installed and used on at least the first 40 or so installations. According to people who operated it it worked quite well.

John Mitchell whilst he had the system did not use it, he manually advance/retarded the sync on the three machines. He later put selsyns on the machines. My intention is to restore it as it was built and installed.

The Cinerama installation in Plaza Sydney was installed second hand from the Roseavelt theatre Miami Beach. The Plaza Melbourne was installed
second hand from the Tech Cinema Buffalo New
Jersey. The Cinerama theatre Christchurch was
installed second hand (in the 60’s) from Kuala Lumpur Malaya (not 100 percent on where it came from). What I am trying to illustrate is that
Cinerama wouldn’t be installing and recycling
something that didn’t work!

I have not been able to get in touch with John
Sittig. I don’t do Facebook or Linked in.
Perhaps someone who knows him maybe they
can refer him here to the Forums?

Cheers Bill.

[Mark Gulbrandsen]

My point it that the final version of the system would have been the most reliable, and at least in the States these systems were obviously upgraded to what ever the later stuff was and the control consoles removed... Only one console exists from a US Theater that I know of. The last version is basically what John Harvey ran in Dayton and at home. My ultimate point being the films are extremely rare and if certain parts of the old system fail it may result in damaged prints. All that stuff is also obviously not necessary to run the films properly.

[Bill Ryan]

Hi everyone,
In response to a private email from someone who wishes to remain private John Mitchell’s gear can run at both 24 and 26 frames per second that is achieved by changing the input sprocket on the projector head and reproducer. I am not going to
pursue the virtues of the servo system versus the
selsyn system. Cinerama did both. What I was trying to find was information. What I have found is people’s opinion. Which is generally in the negative. Please if you don’t have something positive to say about the topic don’t say it.
Cheers,
Bill.

[Bill Ryan]

2CB00F7B-FBBE-484C-BA0B-E128300A5DE8.jpg

FYI

These pictures are of the control rack (rack 5 as
refered to in the earlier diagram). Also is a close
up of the operator controls in the top of each rack.
There would have been one of these rack besides
each machine. Underneath the operator controls is the servo amplifier. The space in the rack under
the servo amplifier would have been the amplifier for the rear speakers, as the amplifier for left side
was located in Charlie booth rear was in Baker
booth and right side was in Able booth.
Cheers,
Bill.

[Bill Ryan]

Sorry about the previous post I can’t get the.
picture of the rack orientated correctly.
Cheers,
Bill.

[Tony Bandiera Jr]

......... I am not going to
pursue the virtues of the servo system versus the
selsyn system. Cinerama did both. What I was trying to find was information. What I have found is people’s opinion. Which is generally in the negative. Please if you don’t have something positive to say about the topic don’t say it.
Cheers,
Bill.

Bill, with all due respect you need to chill and not be so thin skinned. The folks on this forum WILL always express their opinions, observations and experience. The main reason this forum has survived and grown exponentially over the years is that everyone is free to express their opinions without being talked down to.

We are all here to learn and share what we know about all topics, and even if what someone posts is not what you want to hear, it is still valuable information. Also, copping an attitude will ensure that no one will bother to respond to your posts anymore. I can think of a few present and former forum members who found that out the hard way.

Now as for the virtues of servo vs. selsyn, I am gonna say that selsyns have been proven to be very reliable and cost effective for multi projector/dubber purposes, and are less prone to electrical or mechanical issues.

A servo system adds electrical complexity (the servo amp you are trying to fix) and, if I understand correctly what it does to hold/adjust sync, mechanical complexity and stresses by "brute forcing" the projector mech to snap back into sync.

I DO understand your desire to restore the equipment you have as a servo system, and respect that preservation effort. BUT you need to respect the opinions and experience of the folks on here. Because the very folks you insult may know of someone who has the information you need, you need to not turn them away from this topic.

[John Eickhof]

Greetings Bill, I was actually amused by Mark's 'rube goldberg' comment, it personifies the typical process of invention...ideas become reality through improvement in design, sometimes by accident. I have known Mark personally and professionally for over 30 years aside from being a well revered technician, he is quite a mechanical engineer. I believe that the 'purest' approach is not always the best, some things can be overcomplicated as in this case where in my first post I brought to the attention that shortly after the early system like you are working with, was refined and simplified somewhat with better technology, thus Mark stated it well and the systems settled into here in the states was a more simple yet effective way to perform the end result...it is like comparing a simplex to a century...the simplex was over-engineered and the century being much simpler in design reached the same end result, a picture on the screen. A few of us 'old timers' that follow these forums often use 'tongue-in-cheek' expressions and levity to express our opinions. I too am a purest when it comes to motion picture projection and it's history and development, yet I try and keep a sense of humor too...lots of great inventions were perfected by the aid of negativity...I would love nothing more than to see you get the early system up and running....I am still going through reams of technical service books ( ie: Altec and RCA) to see if I can come up with a schematic for you...it gives me a fun research project...In closing...keep an open mind and your sense of humor! We are all striving for the same end game! Besides, if you do get the system resurrected and my health hangs in there, it would give me a great excuse to come visit and see it work! We are here to be of help...

[Bill Ryan]

Hi everyone,
This is a picture of the rack 5 or control rack that went in each booth next to the machine. I had
trouble inserting the picture before. The third unit from the top is the Servo amplifier.
Cheers,
Bill. 649EB010-DCED-4504-90F9-598DF335D4EB.jpg

[John Eickhof]

very interesting! What were the speakers at the top? intercommunications? or actual sound monitors? or both? I would figure the electronics etc. were constructed by engineers employed at cinerama? the chassis you posted pix of does show signs of professionally built chassis, ere there any nameplates or id plates or model numbers on any chassis? for example, when paramount developed perspecta sound, the actual electronics were designed and made by fairchild electronics....for an early set up it does not resemble a 'breadboard' type of construction, however the projector drives do resemble experimental qualities, the domestic us sets I have seen had much simpler mechanical drives etc. There were many 'job' shops in southern California that most likely helped design and constructed the electronics. What does the nameplate at the top between the speaker grills say? The arly brochures show the control station as having four racks with the basic same layout....seems like lots of redundancy and duplicated wiring...can you post a picture of the back side of the rack? thanks, john

[Bill Ryan]

Hi John,
I have all the gear from the three racks that is
machine control panels servo amps etc. But I
only have the one control rack. The equipment was made by Cinerama at Oyster Bay as was the
servo amps the control panels etc. The panel with the two speakers at the top of the rack was the
intercom, one of the speakers was used as a
microphone with a push to talk switch. The booths
could only talk to the console not each other.
There was no sound monitoring in the booths
and indeed in some installations the operator in
the side booths could not see all the screen.
Regarding Marks comments the early systems in
the US were generally all servo systems Sydney’s
system was installed second hand from Miami
Beach, Melbourne system was Second hand from the Tech Cinema Buffalo. They were not upgraded they remained as built. It wasn’t until the MGM era that the later series of machines came out with selsyns. Generally A series heads. The plate you refer to on the intercom speaker is a standard Cinerama plate. Most of the early installations used converted C series heads renumbered into a D series by Cinerama.
Cheers,
Bill.

[Bill Ryan]

Hi all,
To quote some numbers according to in 70mm.
Miami Roosevelt (installation no.28) 12/1956 03/1958 then to Oyster Bay then to Sydney
(installation no.37) 17/9/58 to 2/12/1964 then
70mm.
Tech Buffalo (installation no.18) 16/3/1955
22/3/1958 then to Oyster Bay then to Melbourne
(installation no. 40) 26/12/58 to 2/6/1965 then
70mm.
By looking at these numbers there were at least
38 sets of 3 strip equipment all with servos fitted.
By the way the is no jerking when the servo is operating it is very smooth. John Mitchell used the
differential drive (with his own control system for
about 30 plus years with no problem.)
Cheers,
Bill.

[John Eickhof]

Thanks Bill, you answered my next question...I was thinking the servo system may have been developed for variances in line frequency and voltages found overseas, I have never seen an early installation here in the US, only the later versions and must admit I was not very inquisitive since the installations were idle and had been replaced by 70mm and D-150 set ups...I do recall looking at the picture head and seeing the direct drive and lack of soundhead, and were A series machines. with a 3 phase motor and GE type selsyn attached...and the crude aperture shaker! In fact th actuating fork thing reminded me of the old Powers 'automatic' loop setter shoe of 1909!

[Bill Ryan]

956EFE34-8E87-4477-9D5D-9D646380F0B2.jpg Hi John,
Yes the servo system is also driven by 3 phase
motors (syncronous) these powered off 220v in
Australia and New Zealand 50Hz. There are other. Subtle differences between the A series heads
and the C series heads. Namely the way in which the counter was driven and lack of selsyn transformer.
I will attach a picture of the box with the motor
start resistors and contactors in it.
Cheers,
Bill.

[John Eickhof]

does the amperite time delay tube hold or release the contactors after start up? Whats the tube number? I can look it up for the time dealy...probably 1-2 seconds,,,depends on ramp up speed though...

[Bill Ryan]

Hi John,
I think it holds the contractor in. I can’t get at it at the moment the gear is all packed away at the
moment. I will get back to you on that.
Do you have any Cinerama gear?
Cheers,
Bill.