No 5 Crossbar Tour
ฝัง
- เผยแพร่เมื่อ 29 ต.ค. 2016
- Museum volunteer Ed Mattson gives a tour of the 5XB from Mercer Island's ADams exchange.
This video is captioned, because the 5XB can get loud sometimes ;)
Part 2 here: • Crossbar Tour Part 2 -... - วิทยาศาสตร์และเทคโนโลยี
![[Panel] Sarah troubleshoots Incoming #30](/img/n.gif)
Worked #5 crossbar from 1969 to 1979 as a Switchman...Fun part of my Life!
Tom Scott sent me here :) Great channel.
Amazing. I was 13 and knocked on the door of our local Ma Bell CO and was invited in to see a crossbar switch in real life. What a treat looking back. The one thing I will never forget is the smell of the CO. If I walked into the Museum today, it likely is the same.
I worked XB5 for 15 years and had to smile when you said a
trouble could take 2 minute to two years to find. In the Tarrytown NY XB5 there was
a problem with transfer starts from dial-tone markers during heavy traffic.
This trouble had been in the office for over 10 years. One Saturday, while I
was alone and on a hunch, I decided to check out the master timer controller TM1
& TM2 leads that multiple through the linelink frames. And as I remember
the leads were soldered together in LL Frame 18. I cleared the short and the
trouble which had been in for years was fixed. I would love to see your
operation, however, I’m on the East Coast and don’t think I could make it out
there.
Correction its master traffic controller
Billy, When did work at the Tarrytown CO? I was foreman there from about '75 to about '80, give or take a year.
I worked at the Tarrytown CO from around 1971 till 79 as a switchman, 79 to 84 on and off as a foreman. I remember you were one of foreman. How are you? I Hope all is well. As I recall you moved on before the office had the 101 ESS installed around 1974 and before the SCC was implementatedimplemented. Also in the mid 70's the X5 in TTN was cutover to a XB5-ETS You may also remember John Epp & Lou Hail. I haven't heard about these guys for over forty years. ( Billy Lowe is an Alias. I'm B Voss)
Billy Lowe
Sorry for the delay. Let's connect via email. Bob.bellhouse@gmail
At last another 101 ESS.
Talking about trouble shooting in a 5XB, when I was a switchman, we had a case of trouble that was never solved from my first day until the day I left. I went to ESS, was promoted to management, was a translations engineer - many years went by. We had a strike for about 11 days and I was sent to cover my old 5XB because I had experience, and 5XB people were getting hard to find. I decided to have a run at that old case of trouble, which was still there, and what do know? I shot it. Just followed the detached contact drawings, and the trouble cards. I always said, of my over thirty years with the Bell System, my time in 5XB was my favorite assignment.
In September 1999, our 5XB Crossbar had been cut over to 5ESS. (Bell Atlantic)
I'll always remember the 70's - 99. These machines made A LOT of noise. The sweet sounds of circuits & calls connecting are sorely missed. Wonder if any 5XB are still in service today.
Edit: Every morning at 4am the XB dial tone would change to a Hollow sound. 4am the next day, DT was smooth. Our 5XB did this repeatedly for 35+ yrs.
I doubt these are still in service anywhere, except in museums or owned by some well-off people as a hobby.
@@MichaelWallace-oq3wd Any telephone numbers we can dial to hear those slow step calls going through? I didn't think there were any left, as the maintenance, the lack of knowledge, we've moved onto 5G, VOIP, gig internet, and so on. I remember as a kid the crappy General Telephone overloaded step switches that served our house in the Los Angeles area. Telephone call completion was slow and often failed. The next time I'm up in Seattle, maybe I should pay a visit to Communications Museum.
this takes me back (British telecom) I worked on crossbar and Strowger and just looking at the ladders brought back great memories on the MDF, we used to race each other on the ladders LOL
Yep, I remember the travelling ladders on the MDF's and the big blue gantry's on the TXK3 crossbars, happy days :-)
Here I am working for a phone company just an hour away, watching a video about telecom on break. Always enjoy your videos, Tom!
My dad was a switchman. He loved his job. Sometimes he would bring me into work with him when he was on a callout and I got to see 5XB. I thought it was amazing. He used to complain that the telephone company was going to force him to learn 5ESS but he retired before they roped him in, lol!
Brings back some fond memories of when I first started working as a telecommunications technician. Thank you.
The best job I had in my 30 year career with the company. At age 77 I'd go back and do it again. Very rewarding job.
Best job I ever had, #5 crossbar switchman, Asbury Park NJ, 1970-1977. 2 marker groups, flat and wire spring. Great mental challenges sometimes, lotsa fun, 24 hour office.
Mind-blowing technology and complexity.
great video..........fascinating. The tones used for signaling is how phone phreaking worked, which was the first hacking of a system.
I've been studying the US phone system for the past 40+ years... This is the 1st video that explained how it worked!!! Reading about how this stuff worked and actually seeing it in action is like a dream come true!!! Thanks so much. I;m going to have to watch more of your videos to finally understand what I've wondered about for so long. Dee-do-do-dee-do-do-dee!
Any idea why some 5XB changed dial tone sound every 24 hours?
Yes I hired on in 1973 so I worked with these old timers. Great employees and you didn't dare touch those switches unless you were assigned to work on them. They took good care of them.
No black men working on this equipment...why?
@@dwightpowell6673 It is a volunteer museum. Perhaps none have volunteered.
@@JeffFrmJoisey that's a truthful and honest answer. I never experienced any discrimination as an employee starting with Western Electric until I retired through Lucent Technologies. I had 36 years service experience.
I love this. The original stack trace!
It essentially punches a stack trace into a card as we see in computer programming.
What a memory. I got hired at Western Electric right at the wrong time in 1979, a few years before the breakup. Spent most of my three years tearing out crossbar systems to upgrade to ESS. Loved the sound of a few clicks when I started work and the gradual increase to a constant chatter as people woke up and got to work.
worked in exchanges and customer private exchanges (PABX) in Australia, the relay sounds bring back memories.
I was promoted to technician in 1982 and assigned to work with an old timer with 30 yr experience. These old timers took pride in their work. I worked for Pacific Telephone part of AT&T.
I was lucky enough to get my Switchman's rating in 5XB at New England Telephone. This is music to my ears!!!
SNET !
In Europe we used the Ericcson (crossbar) since very early times. You could spot it because the called party ring begun a second after you ended dialing the number. This avoided the problem of getting a busy tone (with called party free) because all the combinators were busy.
The Crossbar switch was invented by LM Ericsson in Sweden, some of the Crossbar switches installed by Western Electric throughout the US even had Swedish made/labelled shelves - like the ones I saw in Mexico Missouri before we cut it over to an Ericsson AXE Class 5 switch in 1991.
Spent 25 years in XB5/XB1 switching all over Westchester and Rockland Counties in NY. The last 5 years in the ESS world.
Worked 4A Card Translator in 60s, Appreciate the video.
One of the old timers here the guy who trained me hired on in 1950. Back in the day when we employees took price in our work.
Back in 1998, when I was a Nortel DMS100 Equipment Installer, I worked a job at the SBC Hedrick Office, in Overland Park, KS. Between the old part of the building, which faced Johnson Drive, and the new addition in the rear, along Riley Street, there were two separate Switches on the 2nd Floor. The DMS100 Switch was located towards the front of the building, while an older Switch was located towards the back. I didn't know much about Electro-Mechanical Switches back then. After watching this video, I wonder if it wasn't a Crossbar Switch. It wasn't as noisy as a SXS Switch. Wish I would have thought to take pictures back then.
In the Missouri/Kansas Market for SBC, they had a lot of extra bracing, for concerns of earthquake damage to the structure. I would've liked to work on the Electro-Mechanical Switches of the day. So much is automatically done in the Digital EAX Switches, that the C.O. Techs don't have to deal with the issues of the past, or truly understand how things evolved into what we have today. Don't get me wrong, some of the work was no joy, but you had a real grasp & appreciation, of what it took to make things work. For me, connecting those dots is priceless.
I'm enjoying this channel. I'm curious to know how the 5XB does the equivalent of the line finder function from the Strowger and panel systems? Are the brains in the dial tone marker? Is a vertical in a line link frame totally dedicated to my line or is there some other kind of switching involved before my calling line gets to the crossbar?
I worked for Nortel SP1 and I remember it took me 3 months to find a marker block problem, caused by two pins shorted in one specific marker.. The index of the c.o. Performance was affected by this trouble..
I don't know Hedgehope at all but I assume its quite small. The smallest one I saw was at Pukerua Bay, just out of Wellington when I was seconded to Transmission in 1987. I think that was an NC230.
I working in this field 30 years EBAPX in VTC corporation and Mango company in Amman Jordan.
Very cool to see a card from the 4A, I didn't know there were any around.
Now if only we could find a full card translator lying around somewhere ;)
at around 8:20 the test set put some calls up that I don't think either the OR or the flat spring maker liked it. You can hear the OR's tripping up at around 8:23, 8:24. Then the maker locks twice and you can see the delay relays at the bottom left light up and disconnect at 8:29 and 8:32. Can you explain (if you can) what happened? Edit: oh and you can hear the alarm bell which I think is the minor bell and not the major gong.
You heard correctly! That was an unhappy OR and marker. Though I don't remember exactly what happened, its quite likely that the OR stored a bad digit and the marker did not have a path set up for it. Since we have a very limited number of lines, if you dial a line that isn't present, the marker will look for it, and then fail to find it. Having failed, it then does a "marker advance" and tries again. It will fail a second time, and then sound an alarm.
The other thing that could have gone wrong is that it *did* find the called line, but failed to close the crosspoints to connect it. I know at least one line has that problem (it's not a line dialed by the test cart, but maybe the problem effects more than one line).
I use to help to install crossbar along with stronger exchanges with plessey telecommunications in 70s I can remember the crossbar racks being very have to stand up I left to work for The G.P.O. I am now retired after 40 years my last job was at the other end of the network safety checking the poles has a pole tester when I was offered the job I thought I will never be out of work the area more then 3 million poles to check in the U.K.
I remember replacing a vertical on a xbar was a pain..
GREAT video! Waiting patiently for Part 2 - MFing. Soon?
Yes! Glad you enjoyed the video. Ed is on vacation for the next few weeks, but when he gets back, I'll continue filming the MF portion of the tour.
acording to me #5xbar was the most complex switching technology but the greatest one to work on ......35 years at Bell Canada and went trough the Step by Step,\#5xbar,Sp1,ESS,DMS100, an loved my career wish id go back so i feel younger
What is Sp1. I worked42 years at Southwester Bell Tel. Co. and went trough the Step by Step,ESS,DMS100, an loved 35 of those years. never worked #5xbar. Last 7 years were *Hell* because of Metrics.
@@gpwgpw555 sorry thé Sp1 sas developed by northern telecom was the Canadian version of the American ESS it had mini xbar switches and a electronic front end that cimmutator didn't last long the were installed from 1967 to the 80s
Newtown CO, Elmhurst Queens, OL1, NR2 !
Which switch is the off hook tone switch?
Worked from 1974 to 2014 in Puerto Rico telephone company and my first job was switman
I see it! There on the desk at 11:23! A receiver connected to a clamp and a pic. This is the tool they gave me to work on SXS switch circuits.
Awww, it ended just as he was about to talk about MFing. Loved the tour, though. I had no idea about the card translator.
So cool, right? Stay tuned for Part 2!
@@ConnectionsMuseum Could you recommend a more detailed explanation of how the card translator works? (the 5 to 15 min version... I'm sure there are also large books on this somewhere)
I see a lot of rectifier tubes in the racks. Did earlier telephone systems use vacuum tubes for the dial tones, busy signals etc?
There are two sorts of tubes there. The 313 are gas filled tubes. They're normally coupled with capacitors and used in timing circuits, since they can be made to fire at very specific voltages. catalog.spmh.us/weco-catalog/tubes%20-%20electron,%20313,%201,%201964-12-31.jpg
The other tubes are resistance lamps, which provide a variable amounts of current limiting. They're used to protect relays that could potentially be exposed to high voltage if there's a momentary short circuit as a result of normal
operation. catalog.spmh.us/weco-catalog/lamps%20-%20resistance,%2015A%2015B,%201,%201958-12-31.jpg
Tubes were used as oscillators for MF tones used for signaling between central offices until transistor oscillators came along to replace them. Tubes were never used to generate dialtone and busy signals. Those were generated by a ringing machine, similar to the one seen here: archive.org/details/bellsystem_we-fundamentals-of-telephony-lesson-1/page/78/mode/1up
In smaller offices, there were solid state ringing generators, but I'm not entirely sure how they work.
@@ConnectionsMuseum Oh ok, Gotcha! Thank you :)
He's an old timer, I remember these guys. I got used to hearing that sound and when they took them the switch-room went quiet. It was kinda strange.
Yep, when you go from the lively sounds of a XYX or XB office, a DMS office can seem a bit...eerie.
How much was that?
The problem for the Bell System and Long Lines was that the cost of carrying the calls dropped through the floor with the adoption of high speed electronics. Which is partially the reason why today we don't pay for long distance on mobile phones.
Long distance was Always cheep. Long distance charges were hi to supplement Local service. Look at your land line bill. Now after the break up you will see a charge for long distance even if you do not make any long-distance calls. Long-distance charges went down (cost stayed the same). local charges went up.
We don't pay for long distance on mobile phones as competition will not allow it. Has nothing to do with the actual cost. There are some cell plans out there that do charge for LD.
So are the cards a lot like static routes in modern data routing? Also, can you elaborate on how selecting cards works from an encoding perspective? What do the punches on the bottom of the card signify?
That's a good analogy, yes. Before card translators, machines used hundreds of wires connected to crosspoints on an X-Y matrix of terminals. The wires grounded certain leads, which closed circuits which then conveyed routing information to the senders. So, if it was desired to route all calls starting with "411" to an operator, a wire would be connected from the terminal for "411" to the "OPR" class punching, which would then in turn operate a corresponding relay that would cause the call to be routed properly. These wires were only changed when a routing changed. Once every month or so, on an as-needed basis. (Gross oversimplification, but its the best I can do here in a comment).
Card translators came along, because long distance routings were complicated, and changed frequently. In addition, there were several routes between two points, so card could be tried in order of priority, and the cards could be replaced or updated if a route changed.
The original Bell Labs publication on card translators can be found here. Hopefully it answers your questions :)
archive.org/stream/bstj32-5-1037#page/n0/mode/2up
I wish I could own one of those rare PBX crossbar type switches. Maybe someday
No I want a switchboard
Does the crossbar support DSL?
DSL is provided by a DSLAM. Usually they just pass through dialtone from another source and "strip off" the data connection
man get this poor guy a microphone.
I listened so carefully but still so puzzled by how this stuff works. The crossbar system is a matrix of connections that goes from point A to point B, but it must be more complicated than that. How does it know a line is busy and then how does it give a busy signal? When it connected to the far end telephone, how does it ring the phone? When the toll operator had to cut into a number in an emergency, how did the crossbar system permit that? If the circuit is in use, how could someone barge in on it? How did the billing system know when to start billing and when to stop? This stuff is so complex that it’s mind boggling. I remember dialling long distance from a payphone and the operator asked me to deposit $1.25 for 3 minutes. I deposited the change the number started ringing but there was no answer. The operator pressed something that caused the payphone to give me back my change. Later when I tried again the party answered. This time the operator pressed something but the change didn’t come out. It went down into the payphone box. They seemed to think of everything but what mechanism would the operator have access to that would offer coin return or coin keep? Those days are gone now but it’s still mind boggling.
By the way, I think I’m in love with the guy in the plaid blue shirt. Oh my gosh he was as handsome as any man could be.
@@MichaelWallace-oq3wd The operator was still on the line and she said “I’m going to give you your money back. Watch your ear this is loud!” Then I heard this REALLY loud tone that sounded like a ringtone but it was much louder. Then some component banged in the phone and the money came out into the coin return. I thanked the operator. This was in the 1970s. There were no smart pay phones then. At least not that I ever saw in my city. We used pay phones a lot because there were no cell phones.
@@MichaelWallace-oq3wd The tone was not as high pitched as 2100 hz. It sounded like the old fashioned ring tone from step by step exchanges - only really loud. It was amplified like crazy. It made my ear ring afterwards. The operator was right, but I didn’t listen to her.
@@MichaelWallace-oq3wd Yes. It did return my money. I thought the operator was ringing someone because the tone came on for 2 seconds before the money was refunded. It’s just that the ring signal was at such enormous volume. Other than the volume it sounded just like a warbling ring tone.
Whoever's shooting this should be a voice actor. Srsly don't waste that talent.
АТС Пентаконта, супер.
THERE IS STILL A WORKING XBAR OFFICE. I STARTED AS AN SYSTEM EQUIPMENT ENGINEER IN NEWARK N.J. IN THE 1960'S LOCATED IN 2 GUY DEPARTMENT STORE DETAILING THESE SWITCHING OFFICES FOR THE NORTHEAST REGION. WE WERE A PART OF A.T. & T..THEN. I ENDED MY CAREER IN 1990'S BY REMOVING THEM FOR VERIZON. AFTER THE LAST ONE WAS REMOVED VERIZON RETIRED ME WITH A 6 & 6 PACKAGE. THERE ARE NO MORE OF THESE CUDDLE TO GRAVE ANYMORE. THE PHONE INDUSTRIAL TRULY BUILT AMERICA. IN THE OLD DAYS A.T.&T. HAD 1 MILLION EMPLOYEES.
Crossbar is still in use in third world countries.
At the time of the brake up of A.T.&T. I saw a hearing on C-span were an industry spokesman said "We have the Cadillac of phone systems." The congressman replied "Some People want a Chevrolet." Now we are getting that Chevrolet service.
Heh, what?
This guy has no idea what he is talking about. There are no pulleys.
"As these line finders went into service, however, it became evident that 15 brushes on each vertical selector rod were quite heavy, and needed springs and *pulleys* at the top of the frame to compensate for their mass." - Wikipedia page of the Panel switch system
Ok. Yawn. Next video