My last progress report on the PAX restoration was over a month ago. I’ve made some significant progress since then – I just haven’t written about it. Well, I say that. I’m keeping a paper diary, I just haven’t managed to update here (mumble mumble busy at work etc etc)
So In the last month I have:
- Repaired a couple fo damaged heat coils. I’m pretty sure these aren’t a repairable part, and while my repair works electrically, I’m not sure it would stand up to the lighting strike they’re supposed to protect it from. Mind you, I’m not planning on having any external plant hanging off this PAX so that’s probably not an issue.
- I’ve fitted a wooden platform to the base of the PAX, to act as a shelf to hold the batteries, charging equipment and a more accessible connection box for connecting external equipment
- Installed the batteries, with a removable connector to make it easy to isolate the battery supply if I need to
- Fully tested all 4 selectors, I’ve identified two of them as having faults on the called subs side of the circuit. One doesn’t pass ring current on to the called sub, and the other has a ring trip fault. Neither passes speech. This is hopefully just more relays to adjust.
- Desoldered, cleaned up and re-wired a 60 pair “Box Connection” kindly donated by John Bathgate from the DFR
- Desoldered the old 50 pair cable from the tagstrip at the back of the PAX
- Mapped out the strapping on the tagstrip. Which took ages, as there are 500 connections just for the line circuits (and another 50 or so for as-yet-unidentified-stuff)
- Fanned out, laced, and wired in most of a new 50 pair cable from the box connection to the tagstrip on the pax (I left out the lines with unusual strapping until I understand how they’ve been strapped) – that’s what the photo at the top of the post is of.
I’ve still got a lot of work to go, but I’ve got 30 lines available and ready for phones so far. I’ve identified 10 line circuits (spread across levels 3 and 5) which are all strapped for various forms of tie line functionality. This is a bit odd, as from looking at the line circuits only 5 tie lines are fitted.
I really need to get my head around how the tie lines work, but my current working assumption is that it’s currently wired for 5 incoming and 5 outgoing junctions. There are another 10 lines which have unusual strapping, that I haven’t yet identified (they don’t seem to match anything on the diagram)
That is one page of my strapping map. There’s another page of it as well. I’m hoping I can use that, combined with the wiring diagram and a series of train journeys to work out what on earth those last 10 line circuits do!
Oh yes. And I’m building a PC that I can use to hook my PAX up to the internet. More news on that when I’ve finished collecting the parts together.
Automatic Telephone and Electric Company (ATM/ATE) – Adverts
Following on from my post the other week about determining what year my PAX was made, I’ve been digging through old telephony books looking for adverts relating to ATM/ATE. While I haven’t (yet) found any relating to my PAX, I have found some adverts from the same company. So here they are:
From the October 1935 edition of the POEE Journal
From A Handbook of Telecommunication by Bertram S. Cohen published 1946
From Telephony by Atkinson, 1948 edition
From Telephony by Atkinson, 1950 edition
I’ve enjoyed working my way through the 30 or so adverts I’ve scanned so far (you can browse the entire collection here) but now that I’ve started looking, I’m going to have to carry on looking! There must be so much of this material hidden away in books, magazines and journals – overlooked by most people who are more interested in the published articles and the content of the books than the advertising which offset the publishing costs.
A picture of a flower
Here’s a picture of a flower, to balance out the previous phone post. Isn’t it pretty. And Yellow. So very yellow.
So, when was my PAX built?
Since I first got it, I’ve been trying to work out how to tell when my PAX was built. Initially, I thought it was much earlier than it is. My first post here describes it as “1930s” which turns out to be wrong. The initial design of it may be late 1930s, but my example is much later. As far as I can tell, there were at least 3 generations manufactured:
- A cabinet with a “black crystalline finish” – this is the version described in an article from 1938. I’m pretty sure there was a 25 line example of this at Ffestiniog when I collected mine.
- A cabinet with a “grey hammered finish” – wired throughout with silk covered wiring (this is the one I’ve got)
- A cabinet with a “grey hammered finish” – wired throughout with PVC covered wiring. This would be later than mine, and there was certainly an example of this at Ffestiniog.
The company which made it, has had several names, and at least three logos.
- A circle containing the letters ATM, with the company name “Automatic Telephone Manufacturing Company”
- A circle containing the letters ATM, with the company name “Automatic Telephone & Electric Company” (as found on my 50 line PAX, shown above top)
- A circle containing the letters ATE, with the company name “Automatic Telephone & Electric Company” (as found on my 10 line PAX, shown above bottom)
Here’s the timeline my internet research dug up. Most of the links below are from the same site, but that’s only because there isn’t a huge amount of information online about this company:
- 1911 – Automatic Telephone Manufacturing Company established (From Uk Telephone History and History of ATM)
- 1912 – Automatic Telephone Manufacturing Company established (From A history of Plessey, Information & Publicity Services, PTOSL, Beeston. This conflicts with the 1911 date claimed elsewhere, but that may be due to a difference in the definition of “established”)
- 1936 – Company changes name to “Automatic Telephone & Electric Company” or AT&E, keeps the ATM roundel in the logo despite the name change (From History of ATM)
- 1938 – AT&E magazine published, describing the first model of my PAX. The unit is described as having a “Black crystaline finish” – my unit is a gray hammered paint finish so is obviously later (From Private Automatic Exchange Equipments, A new series of designs)
- 1946 – AT&E advert, showing the same logo (ATM roundel, “Automatic Telephone & Electric Company” text) as the front of my PAX (From http://www.gracesguide.co.uk/Automatic_Telephone_and_Electric_Co)
- 1950(?) – Another advert, same logo in use (From http://www.flickr.com/photos/36844288@N00/3726593641/)
- 1951 - An extract from an AT&E brochure, also describing the ”Black crystaline finish”
- 1957 – My 10 line PAX has a stamp inside indicating it’s built to “Diagram S202662/Issue 8″ – my copy of ”Diagram S202662/Issue 8″ is dated 1957. However, this just means it was built *after* the Issue 8 design drawing was released.
- 1961 – AT&E merges with ETL and Plessey (From A history of Plessey and History of ATM - the latter notes that AT&E continued to use the name for a while)
So, based on the paint finish, mine can’t be any earlier than 1951, and based on the company name it can’t be later than “a while” after 1961. Hmm, that’s not satisfyingly accurate enough.
All those dates and still no hard evidence of when my PAX was built. It was at this point, I remembered something from a discussion about relay markings. The 3000 type relays used in my PAXes have markings on the end which tell you useful stuff about any special characteristics the relays have. Amongst the markings it tells you which company built the relay, and (crucially) when!
This extract from Telephony by J. Atkinson (Volume 1, Page 113) explains the markings:
I felt like a bit of a muppet. That’s a much easier way to date my PAX and far more accurate than playing “guess when the logo was used”! So, from looking at the equipment permanently installed in my PAX (rather than the selector cans, which can be removed), I found relays with the following dates:
- 1956,1957 (First 40 line circuits)
- 1960 (Last 10 line circuits. From the looks of the mounting strip, they’re a later addition)
- 1951, 1957 (Ringing, Tones, Misc relays)
Ignoring the 1960s additional line circuits, and assuming that the 1951 relays were a batch being used up (or spares replaced from old stock) I think it’s reasonable to conclude that my PAX was built in 1957. So not quite “1930s” as I originally stated, but still, it was built 54 years ago!
If I take a look at the selectors (which are removable, so unreliable for dating purposes as they could be swapped around) I have dates of 1955, 1962, 1965 and 1969. By fluke, I had arranged the selectors on the shelf in date order! I also note that the very first selector I got working was the oldest example.
While in a new-found-dating-frenzy, I thought I’d date my 10 line PAX. This is a little easier to date as it has had less work done to it over the years. The relays are all dated 1958 or 1959.
With this piece of information, I can deduce that the logo with the ATM roundel was in use from the merger (1936) to some time between 1957 (My 50/7A) and 1959 (My 10/2A) and that the change from silk to PVC wiring also likely occurred at around that time (as my 10/2A is PVC wired)
This weeks photo-challenge theme was “Found” and as I was digging up my spuds this afternoon, it struck me that I was playing an elaborate game of hide and seek with them – looking for them under the ground and digging them up as I found them.
So this is my entry to the photo challenge this week, a small portion of this years spud harvest.