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sparkymike 27th Feb 2020 11:46 am

TXE2 Exchanges
I worked on TXE2 exchanges in early 70's. I can post more details if any interest.


198 kHz 27th Feb 2020 4:02 pm

Re: TXE2 Exchanges
Well I'd certainly be interested, having worked on them from '74 to '80, mainly GEC and STC.
Most of it is now a misty blur, but two numbers I'll take to my grave - CV9507 and CV8805. 😉

sparkymike 27th Feb 2020 5:33 pm

Re: TXE2 Exchanges
I had been living in Canada for a while and came back to the UK in December 1970. I was looking for employment and the next door neighbour popped his head over the garden wall and said if I needed a job, to contact his son,which I did. The son worked for the installation division of Plessey I went for a short interview in Ipswich at a small office they had there in Clarkson Street I think it was. I started work in a new extension to the Felixstowe exchange. Felixstowe was linked to Martlesham Heath Telecom headquarters with the new PCM system.
I had this explained to me briefly by one of the telecom guys and it sounded so far fetched, I thought he was pulling my leg !!
My job was listed as a power fitter. It involved fitting up the racks within 1/16" of plumb, fitting all the tie bars in place, wiring up all the 13amp socket systems in the base of all the racks, fitting up the lighting and wiring up the consumer unit, which was about six feet up in the air, which to me seemed a strange place to put them.??
I also had the job of wiring up the rectifiers and generators.
Going back to the new part of Felixstowe exchange, not sure if this was also TXE2 system, as it is so long ago, but probably was. We had to link the new system busbars to the old which was always a bit nerve racking. The copper link cables were around an inch diameter. I had to solder large lugs on the ends for the links.
After Felixstowe was up and running, I was then sent to the Corten exchange near Yarmouth and Lowestoft. Fitting up these exchanges took around 16 weeks and then we would move on to another exchange. All of these new jobs were empty rooms when we arrived, but looked impressive when we left.
I also did Needham Market, Framlingham, Harleston, Burch in Essex and several others. I ended my work with Plessey at Cherry Hinton in Cambs, as the travelling was getting me down and a job turned up much nearer home.
The chap who started me off was Dennis Beckett, my neighbours son. Another name that comes to mind was Mick Hooper, a very nice chap, who shared my interest in classic cars. He was one of the foremen. The was also another foremen named Gough, who owned a red Morgan sports car. Think he came from the Hull area. I made a lot of friends with the teams I was with and also some of the Telecom chaps.
When I was at Corten, Ivan Grange (Telecom, a group supervisor maybe ?) popped in the see how the job was going and I said hello Ivan how are you. The rest of the team was surprised at my friendliness, but he was my wife's uncle !!
They were good days and we worked hard but also had a lot of fun at the same time. In those days we thought we we building something that would last forever and a day.

Tim 27th Feb 2020 11:07 pm

Re: TXE2 Exchanges
CV8805 Diode? 50 volt 1 amp.
Have a fistful of them somewhere left over from a big job some years ago to link all the exchange alarms in Severnside through TNS(Transmission Network Surveillance-nothing sinister, just linked the the power fail alarms to a central control point if anything went down) from the EOS Alarm unit 54's to the TNS unit. I found the drawings the other day when I was rummaging in my old case tool 23a.......

CV9507 General purpose PNP transistor TO5 case?


Hi Sparky Mike.
My first few years with BT in the late 1980's was on Trunk networks, basically analogue private wires and trunks run over FDM and PCM. It's nearly all gone now.

sparkymike 28th Feb 2020 8:08 am

Re: TXE2 Exchanges
1 Attachment(s)
This photo was the Corton exchange, half way between Yarmouth and Lowestoft. Lovely little site among the trees. Had some happy days there. The chap in the photo was Jamie, if my memory serves me right, a Plessey wireman.
The young Telecom lad apprentice there was sent with a requisition order to the local Telecom stores for a Metric clock. He picked it up and it was fitted up on the rest room wall. It was an exact replica of the official clock but had hours numbered from 1 to 20 !! Someone had obviously taken a lot of time to sign write the new numbers on the dial. Certainly got a lot of people going when they were told we were going over to continental metric hour days . I reckon that clock did the rounds of numerous exchanges.

sparkymike 28th Feb 2020 8:15 am

Re: TXE2 Exchanges
Of course it is now gradually coming back to me. A quirk of these exchanges was that there were left and right handed versions. It was a bit disconcerting to do a stint of 16 weeks or so in a left hand building and then go to work in a right hander. You would find yourself walking into walls where doors should be. Where all the offices were on the left they were transposed to the right.
This was the era where petrol stations were giving free gifts with the fuel, and I ended up with loads of drinking glasses, as we were covering around 80 miles a day.

davidw 28th Feb 2020 10:47 am

Re: TXE2 Exchanges
OK what does " bar FT do"? a favourite question on the TXE2 courses.
I had 5 of these to look after ,the most interesting was the Plessey one used as a pbx at the then PORD (Post Office Research Department) Martlesham (now Adastral Park). Some of the trunk circuits were modified to link in a 4 position manual board!

G6Tanuki 28th Feb 2020 2:11 pm

Re: TXE2 Exchanges
I've got loads of those CV9507 transistors here. All made by Texas Instruments Bedford according to the code.

The ubiquitous diode I remember from exchange-days was the 1N2071 - we had millions of the things and coerced them into all sorts of unusual applications [imagine hundreds of the things wired in series-parallel to use the 0.6v-per-diode forward-voltage-drop and let us use 115V equipment on 230V mains! I have STC New Southgate to thank for learning that one]

sparkymike 28th Feb 2020 3:24 pm

Re: TXE2 Exchanges
I can remember all the circuit boards being removed from their boxes, packed either side in bright coloured foam (Was it green or pink, memory fils me.)
They used to fill a skip with all the packaging.
I now remember the name of the clerk of works at Corton, It was Dave Banyard, a Lowestoft lad I think. Dick Crisp was another at Needham market, he came from Raydon in Suffolk, I knew him as a lad as I lived in same area.
One of the Plessey supervisors was Wally Scott. He wore glasses like those bulls eyes you get in old cottages. I well remember driving home from Harwich exchange, where we had been lifting some racks up to the first floor and there was a real pea souper of a fog and we were reduced to 20 mph or less and Wally came flying past us and I distinctly recall the guy in the passenger sheet looking rather worried. We assumed his thick glasses were X-ray specs !!

Pellseinydd 28th Feb 2020 8:44 pm

Re: TXE2 Exchanges
3 Attachment(s)
I spent most of all my GPO years as a TO responsible for a major hub of the Defence Telecoms Network built just before WW2. After nearly ten years deep underground working on vintage kit, I left and joined STC and started as a commissioning engineer for TXE2. One of the first I was at was the TXE2 at Rhosllerchrugog near Wrexham in North Wales. It was to my knowledge the only TXE2 to directly replace a manual exchange – it was the last manual exchange in the Wales & Border Counties Region. The CBS2 manual exchange was located in a terraced home and still has DP1 (Distribtion Pole No 1) in the back garden. Zoom out and exchange was in the white pebble-dashed end terrace house on the right. When I started with the GPO as an apprentice, I used to visit Rossett manual exchange a two position CBS2 exchange in the front bedroom of No 3 Sunny Villas at Rossett between Chester and Wrexham. Note the manhole in the pavement is still there! The exchange was originally a National Telephone Company one opened in June1907 . The folk who lived in the house worked it at night and two operators came from Wrexham auto-manual exchange to work it during the day. Then I worked during my time as an apprentice on construction of the UAX13 which replaced the CBS2. Then in the early 1970's I returned to commission the TXE2 which replaced the UAX13. Then I was off on a 6 months course before going as senior commissioning engineer at Birmingham 'Rectory' – first TXE4.

Then twenty years later I was offered a complete TXE2 by BT at Llangollen which had just gone 'digital' - they weren't aware that I had commissioned that one as well.!

Some years later I recovered a UXE7 (Unit eXchange Electronic No 7) from Cairngorm which was disused as the subs had been moved off it onto Aviemore exchange when it went 'digital'. The UXE7 had replaced an earlier UAX13

BT only bought 12 UXE7s from GEC around 1981 and all were installed in two groups in the Highland. No more were bought as the UXD5 (modified Monarch sysem came along sooner than expected). The UXE7 was the BT designation for what GEC had developed and sold as the RS22. It was basically a smaller version of the TXE2 which started off with 50 subs, control gear etc in a single rack and could be expaned a unit at a time to several hundred. Racks were only 2 metres high! BT had their own version developed which included a sold state slide-in Coin & Fee Checking circuit card. Also recovered some cards from the last UXE7 in service - Diabaig - way up on the west coast of Scotland opposite the Isle of Skye. It finished in service on the morning of a day in March 1995 when it was replaced by a 'remote concentrator' working over three microwave links back to Torridon UAX replacing the 10 mile long bare copper wire overhead junction route that morning - last one in the UK! It climbed up to over 600ft over the mountains and had been installed before there was a road to Diabaig. The route up the mountain was that steep that the base of one pole was higher than the top of the previous one!

Happy days over a quarter of a century ago!

sparkymike 29th Feb 2020 8:13 am

Re: TXE2 Exchanges
Were they lightning arresters on those poles ?
Did they carry on using the large battery banks in the exchanges or were these scaled down ?
I suppose all those racks and equipment we put up is now around the size of a suit case !!
I did get the chance to have a tour round a Dutch exchange as my Dutch friend's father was a telecom engineer in Baarn. This was a Strowger system.
I worked on Bildeston exchange in Suffolk. That was close to Wattisham air field and the roof of that exchange had an extra thick concrete roof to prevent and damage to the equipment in the remote case of a plane hitting it.I guess that any RAF station had to have a phone system that operated under any circumstances.
How high were the normal TXE2 racks ? I know we spent most of the time working off high trestle ladders. One day a wireman, working on cable lacing on the top grid, lost his footing and me and another fitter, both on ladders grabbed him on his way down !!
Lots of good memories.

davidw 29th Feb 2020 10:01 am

Re: TXE2 Exchanges
Mike, lots of names from a past life,Richard Crisp is still about in Hadleigh I think.
Bildeston exchange was the bain of my life during "on call" weeks as it was for some reason it was badly affected by the remotest hint of a thunderstorm. Many a "happy" night spent driving a vile Bedford HA van through a storm on a 90 odd mile round trip to put it back to normal.
I wonder if our paths crossed Mike? Did you work on any of mine ie Orford, Shottisham, Eyke, Bentwaters, Martlesham.
I also had dealings with Framlingham, Wickham Market, Needham market,Gt Wenham, Leiston to name a few!

sparkymike 29th Feb 2020 7:56 pm

Re: TXE2 Exchanges
Hi Dave,
Bildeston had a flat roof if my memory serves me ok . I also worked at Pakenham. That was a bare building when we got there. I worked with Plessey from 1970 to about 1973 when the travelling got too much for me. If you were around about that time then indeed we might have been in the same place at the same time.
The more I think about those times, the more comes back to me. My mode of transport at the time was an Austin Cambridge followed by a Morris Oxford.I really racked up the miles in those two cars. Other names I remember from the Plessey team were Dave Orvis and Nadine Kemp. There was a coloured guy from the West Indies , a wireman, who always brought in his tape player and treated us to obscure ska !!

Tim 29th Feb 2020 11:02 pm

Re: TXE2 Exchanges
Bedford HA Dave?
That must have been a bit dicey, as they were very light at the back(particularly if empty with 39PSI tyre pressures) and only had single speed wipers.

Not sure what a "bar FT" does, as TXE2 was a little bit before my time. and I never went on the course. Apparently it took two weeks just to learn what happened between the caller lifting the handset, and the exchange giving them dialing tone!

davidw 1st Mar 2020 10:32 am

Re: TXE2 Exchanges
Mike, yes Bildeston did have a flat roof and was built into the side of a hill. The roof was reinforced as it was deemed to be on the flight path of Wattisham.
I remember a Nadine being a wireperson when Kesgrave crossbar (plessey) was put in, late 60s.
Tim,you are right about the course time to dial tone,given that these units where 70s transistor tech with reed switching the complexity was incredible (at the time).
The PO spec HA van had a derated Viva engine producing just 24hp as opposed to the original 40hp , the workshop boys reckoned the camshaft had virtually no lobes!
The driving style was to use the throttle as an on off switch, idle or foot flat on the floor.
During my final days on the road they gave me a

sparkymike 1st Mar 2020 8:03 pm

Re: TXE2 Exchanges
I remember asking one of the telecom chaps, if one of the slide out circuit boards failed, could they repair them on site and he told me that they just sent them back to the maker, who I assume was Plessey.
I also worked at Brentwood exchange and Colchester, but briefly.
We had an incident at the Harwich exhange. A rack was being lifted up to the first floor and it swung outwards just at it was being pulled in and one guy was dragged out with it. I don't think he was injured but close shave all the same.
Those selector racks must have weighed in at half a ton ?

sparkymike 3rd Mar 2020 9:29 am

Re: TXE2 Exchanges
I thought that I should mention the alloy busbars, as at times they caused a lot of consternation. Where there were joints, the bars were overlapped and then a fish plate was put either side of the joint and then bolted together with a bolt at each corner. Before bolting, we had to fettle the joint by vigorously brushing the alloy with a wire brush , under coating of Vaseline. When all the joints were completed, a test was made across each joint with a Galvanometer. The reading had to be zero and numerous attempts had to be made sometimes to get to that figure with some joints being dismantled several times.

GlenTyan 6th Mar 2020 12:03 am

Re: TXE2 Exchanges
I had two spells working in TXE2's twenty years apart, first was as a TTA Apprentice I was sent to Dalry Ayrshire the second TXE2 after Bishopton Renfrewshire in our district, think that would be 1968/9 and I was sent there because my hobby was radio and electronics. Twenty years later I was asked to go round and modify the common control on all the TXE2's in our district a reason which escapes me now but perhaps someone will remember. My boss produced a blueprint diagram one day and asked if could build this circuit with a dozen or so IC's which I said yes to. Unfortunately I soon discovered the pins numbers were reversed which caused a delay but once finished and hooked up to personal PC and plugged into the common control it printed the calling sub when a pair at the MDF was shorted ...i.e A calling sub. The idea was that the frame could be recorded in advance of the upgrade to System X or Y and a real time saver.

I can comment on the problematical Busbar joints, flashing one side of each
Busbar with silver solder I believe was the answer.


sparkymike 6th Mar 2020 9:07 am

Re: TXE2 Exchanges
One of the chaps I worked under was a Taffy James, a rather mercurial guy. He was ok to work with in the mornings, but at lunch time he would visit the nearest pub and turned into a Mr. Hyde and whatever we did was wrong.
He had an Austin A35 van in which he used to sleep, in the exchange car park, wherever we were working at the time, as he then could save money on board and lodging.
I often wonder if his liver got the better of him.
Dennis Beckett joined Ericsons or Siemans (I forget which)and moved to South Africa to work on their equipment there.

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