My time at Rank Bush Murphy

[hans]

In Norway 26" was the by far most common size in the 70 and 80's. As I might have said before UK sets were rare here. The Z718 sets were an exception. They were imported by a store chain here and sold as a budget sets. Of the sets I encountered all but a few were 26". The rest were 22".

I found these sets easy-ish work on, but I found the picture quality to be a bit bland. I only encountered one set that I think was a T20. This was also a 26" set. Other than that this was all I saw from Rank.

[dazzlevision]

This thread has mentioned Bernard Rogers - Director of Engineering at RRI and the concentration of all RRI design and manufacturing operations at the Plymouth factory.

I thought you'd like to see a photo of Bernard Rogers and Angus Crichton-Miller, the Managing Director of RRI, which were in a Bush catalogue from the late 1970s.

[Vintage Engr]

Now there's a name,

Angus Crichton-Miller was one of my bosses when I worked for the Rank Organisation in Brentford.
He got around a lot.

David.

[jayceebee]

Originally Posted by hans

In Norway 26" was the by far most common size in the 70 and 80's. As I might have said before UK sets were rare here. The Z718 sets were an exception.

I’ve seen pictures of an A823 set sold in Denmark which had a heavily revised PSU. The LT supplies seemed to be regulated with a TO-220 pass transistor rather than that massive 18v zener which UK sets had. Still had the same heat issues as the UK version, the PCB looked well and truly cooked.

Don’t suppose anyone has any circuit details for the Scandinavian version? I’m currently on with a Kicad project to produce a new PSU PCB for one of my sets which is badly toasted and would like to try adding the series regulator.

John.

[Sheppertonian]

There were earlier mentions in the thread of Bernie Rogers and his role in the development of the PAL system. In the ‘60’s I worked in the BBC Designs Department and also worked on the development of the European colour system (and from 1971 in the BBC equipment department around the corner from RBM in Chiswick). They were heady days with several different systems proposed as alternatives to the NTSC system (and yes, it was called Never Twice the Same Colour, but I didn’t realise it was coined by Bernie). The other main system was SECAM (System Entirely Contrary to the American Method) that used FM modulation of the colour carrier. The BBC lab head was Gordon Parker, another notable name was Peter Tingey, originally from Echo but joined the BBC in about 1965. I met Bernie on a number of occasions and visited RBM in Chiswick.

The PAL system was actually invented by Walter Bruch of Telefunken and was made possible by the development of glass one-line delay lines. The development and refinement of the system was very much a joint cooperative effort between industry and the broadcasters. Exciting times.

David

[Nuvistor]

What I couldn’t understand about RBM, was all that knowledge and experience didn’t didn’t produce CTV’s with as good a picture as other makes of set. The CTV25 was ok but other dual standard sets gave better pictures, then the A823 chassis, again other makes did better.
Of course that’s my opinion, others may think differently.

[Heatercathodeshort]

The single chip version of the 823 gave better pictures than the two chip version. Some of the later ones were truly dreadful [varicap models] but at the time, talking to RBM technical, I was told that drastic modifications were required to improve performance. Odd thing was I cannot remember a customer complaining about it but the service guys certainly did!
My first colour receiver was a dual standard Murphy CTV2210D and it gave excellent pictures for over eleven years.
From the period between the TV125 to the A640, RBM chassis were not 'nice' John.

[Nuvistor]

The TV135U hybrid was a decent set for me, we sold many and service calls were very rare, many were 5 years old before a first call.
The TV135R all valve set was a different beast, very poor.

[Heatercathodeshort]

Yes the TV 135U hybrid was a rare beast in my part of south London. Huge numbers of the TV125 series and the later TV141. John.

[Welsh Anorak]

I was puzzled as to why the CTV25 gave a poorer performance (brick instead of red) than the Decca or GEC which used very similar decoders and CDA stages.
I agree, the single chip dual standard 174/2210 and later A823 was fairly good, though not exceptional. Oddly, the Z179 used the SL901/918 and produced excellent pictures, so the ICs weren't to blame. I must admot the 2-chip A823 was the only set after fitting a new tube to make me wish I hadn't bothered.
The T22 and T26 gave good pictures, as good as any other 20 or 30 AX tubed sets .

[dazzlevision]

Originally Posted by Nuvistor

The TV135U hybrid was a decent set for me, we sold many and service calls were very rare, many were 5 years old before a first call.
The TV135R all valve set was a different beast, very poor.

I agree that the hybrid Bush TV135U chassis was very good, as it provided the reliability of transistorised RF and IF stages and the proven TV 125 power, sync, timebase and EHT ciruitry.

In addition, the low power pentode half of the PFL200 was used to provide some black level stability/correction.

The TV135R and the derived TV141 chassis were awful.

The hybrid successor chassis to the TV135, as fitted in the TV145, with very similar circuitry, was let down by the omission of the black level correction feature and ac coupling of the video signal to the CRT's cathode.

[paulsherwin]

Thread reopened by request.

[G8vsjDave]

As already explained, in 1974 RBM moved their television development departments from their factory in West London to the production factory in Plymouth.
Just before the closure, management decided to dispose of the contents of a store room that was used to house old, lab built pre-production ‘A’ and ‘B’ model televisions and tubes. It was decided to offer the contents of this store room to that the engineering staff who, in exchange for a small sum of money, could choose what they wanted.
Colour set were sold for £5.00 each. Monochrome, £1.00 and spare colour tubes 25p. Yes, Really.
I came away with a ‘A’ model Z718, 18 inch colour set that had been built in the Lab and used for final development. Before taking it home I cleaned and tidied it’s circuit boards and because it was lab built, and has a ‘live chassis’, I made sure it was safe to use in a home environment, (my bedroom). A year or so later I gave the television to my Girl Friend who, after another year or so, in 1979, became my wife. We used the Z718 as our family television until 1999 when I inherited a 21 inch model and the Z718 was wrapped and placed in the attic.
This Christmas I decided the it was time to get the old girl out of the attic and add it to my small collection of old Televisions and Radios. I placed it next to a radiator with the back removed and left it for a month to dry out and this week, I stated to play.
A quick visual inspection showed a capacitor on the scan drive panel had leaked, and a 100 ohm resistor (R13) had left a vertical heat mark on the Line output panel. I replaced it with a 1 watt resistor and mounted it clear of the board.
The leaky capacitor was C18 and it is part of the ‘kick start’ circuit. The line oscillator (TBA950) is supplied from a low voltage winding on the LOPT, however at switch-on, the line oscillator must first be running to drive the LOP stage and generate the low voltage supply, (Chicken and Egg). This is achieved by a 10uf capacitor (C18) from the HT line, charging a second capacitor (C17) that feeds the line oscillator enough volts to ‘kick start’ the system, after which power comes from the LOPT.
I cleaned the board and replaced the capacitor with one half the size and twice the voltage rating, then noticed while cleaning, I had damaged a transistor on the PCB. On taking a closer look I found the transistor had only two wires so it would need replacing, but I couldn’t find it on the circuit diagram. Looking through my collection of Rank television data, I found a very early pre-production circuit diagram that showed the transistor. The circuit configuration in my set (see Pic 1) had a one transistor 12 volt stabiliser fed from the 30 volt line. This was later changed to the 12 volt line thus eliminating the transistor (Pic 2). I decided to modify the board and fit the more recent circuit.
A thorough inspection revealed the lack of the anti-breathing circuit on the LOP panel, and several resistor value changes in the width modulator compensation circuit, but I decided to leave well alone. Interestingly, I noticed a Mallard development sample C101 chip in the colour de-coder. This was later to become the TBA800.
I spent an hour re-forming the main electrolytic, then switched on. Apart from some pots needing a squirt of switch cleaner, the old girl came on with no trouble at all.
Dave

[Vintage Engr]

Wonderful 'staff prices'!

You have certainly brought back a few memories to me. I still have my original manual for that chassis, & the 'convergence-pot twiddle-stick' (which should i think have ben left clipped to the chassis)...
By the time that chassis came out, I had moved out of domestic TV & was working for another division of the Rank Organisation.

We used this chassis a lot in hotels abroad, so I must have handled hundreds of them.
Great to hear that your prototype model is still functioning.

David

[G8vsjDave]

I’d forgotten about the ‘twiddle stick’. I modified one by adding a biro top so I could clip it to my lab coat. A few days later the twiddle stick vanished only to re-appear some time later in one of the senior managers top pocket. Good days.
BTW, I’ve got Pic 1 and Pic 2 the wrong way round.
Dave

[Spanfree]

Thanks for the memories. I joined the apprenticeship scheme Aug 1968 and left to join Motorola Semiconductor 1974. I notice there has been some interest in Bernie Rogers. I think you will be interested in these:-


https://rts.org.uk/article/obituary-...gers-1929-2019

http://news.bbc.co.uk/1/hi/england/n...re/4507818.stm

[dazzlevision]

I heard some years ago that Bernard Rogers had changed gender.

I have a Bush catalogue from the T20/T22 chassis era (IIRC) with a group of RBM/RRI employees from a selection of the company's departments on the front cover, including the then Bernard Rogers (on the far right, with beard).

[Welsh Anorak]

The first picture shows a 'conventional' delta-gun convergence board for comparison with the 20AX.
It's certainly not RBM - where was it from?

[dazzlevision]

Originally Posted by Welsh Anorak

The first picture shows a 'conventional' delta-gun convergence board for comparison with the 20AX.
It's certainly not RBM - where was it from?

Fibreglass boards, so unlikely to be for consumer CTVs.

Maybe a Mullard/Philips development prototype (looks like they're all Mullard/Philips made individual components on the boards).

[Wendymott]

I just came across this posting.. When I was a TV repair apprentice in the 60's our shop was an independent trader, not aligned to any factory, but my favourite TV of the time was the Bush TV125 / Murphy V849?? But as with any TV manufactire there was always an Achilles heel. Notably, The VHF Tuner and its variable permeability tuning. Great idea, that Nylon rod with the brass bushes moving up and down the tubes containing the inductors, except a year or so in, the rod would break , fortunately they were not difficult to replace, but a "good earner". Then many years later I became service manager at NEI in Bradford. (1980) Two of our Joint MD's went to Plymouth to the "fire sale" of the Bush factory. Thinking they knew best, "money men always do", came away buying a large amount of Over head TV transport ironwork, A Big crate of "Air power drivers" and a Colchester lathe. The only item worth anything was the Colchester, which I made good use of. We already had Hios electric drivers. All the rest was stored in a warehouse somewhere in Bradford and was eventually scrapped. IF ONLY the technical department had been consulted, another waste of money.