Telephone Switching > General Switching Discussions

Any Switchers out There? Xbar, SxS

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I thought I'd post a couple pictures to see if very many of you out there liked switching.  I haven't seen much on the forum about switching before.  I figured some of you out there have to be interested.

These are all old pictures I dug up.  If anyone wants close-ups of anything in-particular or has any questions, don't hesitate to ask.

The first one is a WE 755A Crossbar PBX.  It has 4 outgoing trunks and 20 stations.  The stations are numbered 20-39.  It can have 3 communication paths at one time.  This switch is particularly neat to watch operate as it "stores" the first number you dial.  If anyone is interested, I can take a video of it operating. 

On the right of the photo is a demo SxS switch my dad and I built a while back.  It has one linefinder, two selectors and a connector.  It has 4 digit station numbers and of course "dial 9 for an outside line" which is hooked to the crossbar.  On the back wall there's an ivory painted WE 1A2 shoebox.  The black box is a WE 820D Merlin system.

The other two are of the big Strowger switch.  My dad and I put it together from AE central office pieces.  The framing was actually left in the basement of our building.  The building we are in is an old telephone office.  It used to house a Stromberg Carlson X-Y system.  When the telco moved out, they just tossed a bunch of the racks and such in the basement.  We sandblasted and repainted some of that and used it to mount our SxS equipment to.

The bottom is the linefinders, 20 switches, 10 sets of line and cutoff relays to run them(each L&CO enclosure has 2 sets of relays).  The upper two rows of switches on the left(above the linefinder switches) are selectors and the two on the right are connectors. 

For those that don't know, when you take a phone off hook, a linefinder automatically zips up and around to "find your line" and give you dialtone.  A selector steps up to the level of the first number you dial and steps around automatically to connect you to another selector(depending on how many digits the number is).  A connector steps up the number you dial and around the number you dial, thus connecting you to the line you're calling.  This system uses 3 digit numbers, so when I pick up the phone a linefinder goes up and around to give me dialtone.  I want to call station 501.  I dial a 5.  A selector steps up to the 5th level, then zips around to connect me to a vacant connector.  I dial a 0, the connector steps up to the 0(10th) level.  I dial a 1 and the connector steps over 1 and rings that station.  I apologize if that's difficult to understand, it's rather hard to explain without being able to explain as it's actually working.

The most significant part of that project so far was the linefinder shelf.  The bank of 20 switches and all of the line and cutoff relays that go along with them are on one big frame.  The original frame we had was cut in half between the switches and the relays, so all the wiring between them would have to be spliced.  Luckily, we located a complete linefinder bay.  The switches can come off to make the whole works lighter, but the L&CO relays don't.  My uncle had to help us get that in the back door of our building with a forklift!  There's a picture of it sitting on the floor when we got it and another of us hoisting it up.

Well, that's all for now.  I'll work on videos the next time I get the chance.


Hi Eric:

Yes there is at least one "wanna Be" switcher here. I removed and junked enough stuff (working for the Telco here) to fill warehouses and now I wish I had kept some of it.

Thanks for posting your pictures and telling their story. Is all of your switch gear at the office building or is some at home? Is the big switch AE or WECo?

I do have a single shelf of AE SxS switches wired into a demo unit that can process a 7 digit call. It was used in our training centre until they no longer had a need for it and then I got lucky as an installer that knew I was into this sort of thing was asked to get rid of it. It has been following me for about 25 years now.

I also have a dream to get a 200 line CDO (200 line SxS trailer from a small town) brought to Vancouver and restored to working condition. I had heard rumours of its existence and finally found it and took pictures in September 2009. Here's a link to the pictures on my Photobucket site.


Here's a PBX thread from early 2010 that gets away from the Panasonic 616 theme and onto some "Real PABX's"! So there is at least some switching interest. Maybe we need a switching category??

I posted some pictures of a "Real PABX" in this thread.


WOW!  I completely missed the pictures of that Hitachi Crossbar, that thing is cool!  Our big switch is AE.  The switch racks look incredibly similar to the pictures of the equipment in that trailer(which you better get your hands on!)  All of our stuff is at the old phone building, the house isn't quite big enough.  My dad put a comdial system in our house(because it runs on just 2 pairs), but I didn't like it.  At some point when I was in high school I put a Merlin 410 in my bedroom because I wanted to use my burgandy Merlin phone, and sometime later I added a red Trimline.

My dad used to work for a 2-way radio/telephone/alarm company.  He remembers in the late 80s or early 90s they removed a WE crossbar PBX from a local hotel.  He's always said it was a 770.  From the way he's described it, I think it was a 756.  All of it went into the dumpster except for the power supply which is now running our small SxS demo switch.  Both of us wish we could go back in time and slap him for not taking it!  It's sad how little of that equipment survived, it's such neat technology.


When I was younger, I was always amazed as to how many things a phone and Central Office could do with only a couple of wires. It wasn't until recently that I began to play with phones that I realized all that happens behind the scenes to make a call go from one phone to another.

Keep the articles coming. Even though modern electronics have reduced the capabilities of relays down to microscopic transistor based switches, nothing compares to the sounds and sights of old switching equipment.


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