Hey guys, I think I have become addicted to a switch.
Ever since I watched Fran Blanche’s recent video where she takes apart one these
Apollo ground control switches, I knew I had to have one. I highly recommend you watch her video.
These lighted switches were used in copious amounts in the Apollo Mission Control rooms.
And it is just one of the most awesome and over-complicated vintage switch I have ever seen.
So I got one to test my HP calculator clock modules timing prowess in one of
my previous episodes. Since then I have been able to snatch a few more
and not only has my collection grown a little bit,
but I am starting to understand a little bit more about the taxonomy of these wondrous switches.
They were made by the Master Specialties Company of Costa Mesa, in California, next
to Newport Beach in Los Angeles. But apparently for a while they were part of Eaton, so you see
identical parts branded Eaton. I also bought some branded SAGEM, the French industrial company.
Their brochure claims that they made the finest in illuminated switches. And they
really did. And their marketing department went on overdrive when it came to naming the products.
The Apollo switches are from the top of the line Twist Lite, or series 10. It is so very well named
because you extract and rotate or twist the button to change the bulbs without needing to dismount
the switch. But they are other equally aptly named product series. For example there is a lower cost,
much simpler switch called the Tellite, because of course it tells you what the switch is doing
via its lighted display. Guess what the Fuse Lite switch extra functionality is?
And my favorite is by far the Roto-Tellite. It’s a bit hard to guess what this one does,
but it will become completely obvious when I demonstrate it later.
But back to the main feature of the Twist Lite. The one I just showed is
from the original series 10, where the light assembly just separates out when you twist it.
But they even improved on this with the series 10E. In these switches, the light block is
actually on a sliding hinge, and keeps attached to the body of the switch when you pull it out.
And I just happen to have one of these in my latest batch. Pull it out, give it a twist,
pull some more, oooh, aaah, it stays attached! Now how cool is that.
Note that there is a direction you have to respect when putting it back together. No Mr. Noddle,
the other direction! [children voices]: No! No! And that’s obviously on purpose, so you
don’t get the lettering upside down. [children voices]: Yeah Mr. Noodle! Very good Mr. Noodle!
These things are just unbelievably modular, everything is customizable.
On the indicator portion of the switch alone, you have a choice of bulbs that you expect,
different low voltages or neon. But also bulb wiring, were several bulbs are pre-wired together.
Here are dizzying array of versions you can get, on the wiring alone.
You can have color via little rubber color covers that slip on the bulbs,
or on the background screen itself. The first switch I got had blue covers,
and these don’t make your lights blue, but they make them look whiter instead.
I also got a switch just like Fran, with amber and green little condom covers,
to color half of the button accordingly. But you could also have color in the background
diffuser itself, which was apparently widely used in the MOCR arrangement.
The bicolor arrangements have a diffuser screens splits in two sections. Also note
how the diffuser is distinct from the front lens which I have partially pushed away here.
But I did not expect so many split-screen options. Basically any combo you can imagine is available.
Which brings us to the lens, the piece of transparent plastic sitting in front
of the screen. The lettering is etched at the back of it and well protected,
and had to be customized on order. But wait until you see the available marking options.
Yes sir, this is what true customization and made to order used to mean.
And what if you need better EMI protection? They have an option for that too,
that adds a metallic screen behind the diffuser to prevent electric fields from leaking out.
Actually, my bicolor switch has that option. You can see it right here. And
of course you have different versions of it depending on how your screen is split.
OK, we have not even made it to the switching part yet. As in the rest of the switch, the switch
block is entirely modular. It’s interchangeable and snaps on and off to the back of the switch.
I have examples of two different types in my little collection, the alternate off/on and
the push button style. But there is a lot more, including some with electromagnets to implement
lockouts, and silver, gold, and bifurcated contact versions with different ratings and reliability.
Speaking of reliability, there are MIL spec version of these switches. These are marked 10H
(instead of 10A or 10E), and I imagine this is the type that was used in Mission Control.
I have one type H in the collection. They look identical, but you can see the serial number
starts with 10H. I believe the biggest difference is in the higher reliability contact blocks,
which are different part numbers for the H version, and are of a different color.
I’m skipping over a few more options so we can get to another awesome feature of this switch:
the panel mounting scheme. You mount the switches by sliding them from the front, then inserting
the sliding sleeve from the back. There are trick screws at the bottom that will come out,
and catch and latch on the sleeve, then push it against the panel. The screws are actuated from
the front, you can see them at the bottom of the switch. The switches are so engineered that you
can mount then right next to each other, touching with no separation. You don’t even have to make an
individual cut for each switch to make a row or a column, you just need a single elongated slot.
With that many options, and insane part number codes, it’s pretty hard to know what you buy
when you are getting a switch. More often than not, you’ll get only part of an assembly
and it will be missing bits and pieces. This one is missing the front lens and the switch block,
and has a dark bezel. These have the switch block, but are missing the diffusion screen,
lenses and lamp filters. You rarely get a switch that has a label you can use
iether, so when I found new old lenses, I bought a whole bunch.
Also you want to be careful as there are switches that look similar
but are different, usually simplified models - the originals must have cost
a fortune to manufacture - such as the Series 12 Twist Lite II or the Series
90 Tellite. Or just take advantage of it and buy cheaper switches that look almost as good.
So here is the state of my little collection, I have almost enough to make a little universal
control panel for all things Apollo. But what is the one on the far right?
You guessed it, it’s our famous Roto-Tellite from the beginning of the video.
I don’t know if they used them in Apollo, but it sure looked like I could find a use
for one in my setups. I was befuddled for a bit when I tried to get access
to check the on the bulbs. There was no obvious way to get to them. But wait. Ah, there you go.
Roto-Tellite - get it now? You can change the bulbs right from the front!
And they were GE 345 6V lamps with a midget socket, the perfect type for this unit.
Will they still turn on with a little bit of 6V? You bet, still works just as it should.
So I’ll leave you on this nice family photo.
As they say, they don’t make them as they used t o! See you in the next episode!