My time at Rank Bush Murphy - Page 4 - UK Vintage Radio Repair and Restoration Discussion Forum

samjmann · 16th Mar 2022, 11:32 pm

I worked for a RBM dealer in the 70's, the above brings back so many memories. One horror story stood out. You could interchange Z718, T20, T22, T26 signal panels, as they shared the same size and plug patterns. But the RGB amp supply was quite different...

One engineer in a blind rush fitted a T26 signal pcb to a Z718 chassis. The RGB output stages on the Z718 ran at 300V. The T26 at 150v. So the board was slowly cooked. It came in with the RGB stages burnt beyond repair, the pcb was jet black.

Fortunately no one was hurt, and the set was a rental so it got sorted out internally. But I never understood why the pcb's could be interchanged to such different chassis.

It must be 30 years since I last worked on so, my figures may be out a bit

The T24 was another oddity. All the Toshiba bits ran cool and never failed. The European bits all went wrong. User controls and CRT, all European... No wonder the Japs wiped out TV building in the UK. Admittedly all we saw was a basic 20" for rental, but this was quite depressing.

My Dad told me about 1982 time of a film made for TV of the Toshiba merger with RBM. I never saw it then, but perhaps someone has posted it on YouTube.

SJM

Welsh Anorak · 17th Mar 2022, 3:38 pm

Most of the T24s we saw (and they weren't anywhere near as many as the T22s!) had Toshiba tubes fitted and, guess what, they never failed. The on/off switch, buttons and tuner were a different story. As I said earlier, the only Toshiba part to fail for us was the 36k resistor feeding the sandcastle pulse to the decoder going high in value which became something of a stock fault.

Going back to the OP, I am surprised the T20 series was developed by a different team to the Z718. The chassis, frame timebase and, as said above, the IF/decoder were all very similar. It's like a manager gave the team a Z718 and asked them to make it work a 20AX tube.

And what's with the Z prefix? A680, 774, 816, 823 - then the Z arrives, just for the 718 and Z179. Perhaps should have been Z719 - would have made more sense.

stacman · 17th Mar 2022, 4:12 pm

Quote:

Originally Posted by Welsh Anorak

And what's with the Z prefix? A680, 774, 816, 823 - then the Z arrives, just for the 718 and Z179. Perhaps should have been Z719 - would have made more sense.

Probably at a time when manufactures liked to put a Z or X in model numbers to make it sound 'modern' and the latest technology, even more so with an LED on it,

Heatercathodeshort · 17th Mar 2022, 4:13 pm

The tuner in the first production C2290/24E Toshiba used the Rank tuner but was soon replaced by a Toshiba unit. I can't remember replacing the ON/OFF switch. I guess it was similar to the one fitted in the Dixons own brand model, I can't remember the name, with a Toshiba 'kit' chassis fitted from a much earlier model. I certainly replaced a lot of those! John.

Cobaltblue · 17th Mar 2022, 4:16 pm

Quote:

Originally Posted by stacman

And what's with the Z prefix? A680, 774, 816, 823 - then the Z arrives, just for the 718 and Z179. Perhaps should have been Z719 - would have made more sense./QUOTE

Probably at a time when manufactures liked to put a Z or X in model numbers to make it sound 'modern' and the latest technology, even more so with an LED on it,

More broken quotes I will fix it please preview before posting

Cheers

Mike T

Heatercathodeshort · 17th Mar 2022, 6:06 pm

CONTEC That was the brand with the TOSHIBA kit chassis. Very reliable. I think RBM used the SABA chassis in their first colour portables. Not bad but it seemed to be plagued with shorting diodes. J.

slidertogrid · 17th Mar 2022, 8:02 pm

Wasn't there a set badged Triumph that was the same as the T24?
I found one of those Contec portables near the skip at the house clearance place that I have had a few sets from, the on off switch was knackered on that set, it wouldn't latch. I wish I had saved it now but in my defence it had got very wet!

MickMcmichael · 17th Mar 2022, 8:45 pm

Yes Rich. Triumph was the name used by Curry's rentals back in the 80's. I'd never heard of them until Visionhire bought Curry's rentals out around 1985. All of a sudden we had a deluge of Triumphs and Grundigs coming in off rental as well as all the extra other work we'd just taken on as Serviscope. I believe there were some T24's amongst them. Also lots of Orions badged Triumph too.

G8vsjDave · 19th Mar 2022, 11:48 am

Glyn wrote:

Quote:

It's like a manager gave the team a Z718 and asked them to make it work a 20AX tube.

You are probably not wrong. The new development team would have leaned on previous models as a starting base.

Quote:

And what's with the Z prefix? A640, 774, 816, 823 - then the Z arrives, just for the 718 and Z179.

Yeah, I could never get to the bottom of the prefix letter, in fact the whole project numbering sequence never seemed to follow any logical order . The 'Z' prefix was used for a lot of audio projects and subassemblies.
Dave

Heatercathodeshort · 20th Mar 2022, 12:14 pm

I seem to recall that RBM marketed a 110 degree 26" Delta gun receiver possibly of German origin. I only came across a single example but I no doubt have the manual due to RBM forwarding a manual for every new release together with a copy of 'Service Skill' It will take too long to find it! John

Welsh Anorak · 20th Mar 2022, 3:20 pm

I think that was the Z179. I also thought it was imported until I looked inside and saw an SL901 and SL918, and the manual confirmed it was a British TV. Hinge down PCB looking fairly conventional apart from the decoder. Used an A66-140X 110 degree CRT.

1955APREN · 21st Mar 2022, 2:18 pm

I did not like Z718 as field eng lots of complaints regarding not starting
from cold, fault did not show on visits . I seem to remember that this was due line osc line driver stage start up circuit .

I acquired a T24 with a triumph badge on this one was BER by our work shop staff
as it had seen a very large voltage going in via the aerial lead the pc was blown to bits, having fitted jumper leads across all burnt up pc and fitting
a new aerial socket set work fo the next 8 years till he crt went low. what a great set I loved them
Derrick

Heatercathodeshort · 23rd Mar 2022, 1:08 pm

Thanks Glyn. I thought a 110 degree delta existed but they were very rare. All that tooling up for a very small production run. John.

slidertogrid · 23rd Mar 2022, 2:05 pm

The Pye 731 series used a 110 degree delta gun tube. All that extra raster correction with it's effect on reliability and cost just to shave an inch off the depth of a set! Later on Pye realised buyers weren't bothered about slimline, just price, so they brought out the 725 with a 90 degree tube, simpler chassis less cost and (a bit) more reliable. Wasn't the G9 also 110 degree delta? Only saw a few all 26" sets I don't know if they made a 22" ?

Welsh Anorak · 23rd Mar 2022, 3:06 pm

Yes - they Pye 731 drove a 26" 110 degree tube and, unusually, a 22" 110 degree as well. As you say, the 725 90 degree chassis was much better, though the bar was set pretty low...

The G9 used the 110 degree delta CRT, only 26" (A66 140X) as far as I remember.
110 degree sets using this CRT were much more common on mainland Europe, with sets such as the B&O 3400, Philips K80, Tandberg CTV2, Grundig 5010 and Telefunken 711 to name just a few that made it over here (the latter I wish hadn't!).

The Z179 even looked German which I assume was RBM's intention. In fact RBM were conspicuous by their absence in the 26" stakes - did they ever do one in the A823 or T20 series? If they did, I've never seen one - the old 25" sets were the largest I saw besides the Z179.

slidertogrid · 23rd Mar 2022, 4:04 pm

Now you come to mention it I can't remember a 26" A823 or T20 either . 25 " early A823 yes, they must have made one though as the Zarach Tv mentioned in the other thread seems to have used a 26" A823 as the donor set. Maybe they were made but didn't sell well.
Another anomaly that springs to mind was the Ferguson TX stereo TX10 or 100 Thorn never made a 26" set for retail, only for the rental outlets badged as Baird or DER.
When I think about it in the 70s and early 80s we didn't sell that many 26" sets compared to 20 and 22". The thirst for bigger screens seems to have come along a bit later on. That said most of our customers didn't have large houses with large rooms!

Heatercathodeshort · 23rd Mar 2022, 5:31 pm

These cards from the 1-1-70 service manual show that there was a 26" version made and a number with the later varicap tuner version.

I had never thought about it but I can't ever remember seeing one! I had a 26" version of the Z718 complete with Prestel terminal. It worked quite well but unfortunately like so many other interesting receivers were skipped when I closed the shop in 2003.

line sync · 23rd Mar 2022, 9:15 pm

There were quite a few 26 models fitted with the A823 chassis , i owned a 26" murphy with folding doors years ago.
It would be interesting to here if dave can tell us any think about the A823 chassis ?

Robin

davidh1041 · 23rd Mar 2022, 9:30 pm

Have to say i have really enjoyed this thread, very interesting. Here is a picture of my 26" Bush A823

neil29 · 23rd Mar 2022, 10:00 pm

I've got a Bush CTV197C and a Murphy CV2612C and a 26" Z718. and several years back i did have a 26" T22 that i broke up unfortunately.

Cheers
Neil.

16th Mar 2022, 11:32 pm	#61
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 653	Re: My time at Rank Bush Murphy I worked for a RBM dealer in the 70's, the above brings back so many memories. One horror story stood out. You could interchange Z718, T20, T22, T26 signal panels, as they shared the same size and plug patterns. But the RGB amp supply was quite different... One engineer in a blind rush fitted a T26 signal pcb to a Z718 chassis. The RGB output stages on the Z718 ran at 300V. The T26 at 150v. So the board was slowly cooked. It came in with the RGB stages burnt beyond repair, the pcb was jet black. Fortunately no one was hurt, and the set was a rental so it got sorted out internally. But I never understood why the pcb's could be interchanged to such different chassis. It must be 30 years since I last worked on so, my figures may be out a bit The T24 was another oddity. All the Toshiba bits ran cool and never failed. The European bits all went wrong. User controls and CRT, all European... No wonder the Japs wiped out TV building in the UK. Admittedly all we saw was a basic 20" for rental, but this was quite depressing. My Dad told me about 1982 time of a film made for TV of the Toshiba merger with RBM. I never saw it then, but perhaps someone has posted it on YouTube. SJM __________________ It's never been right since we've had it... Last edited by samjmann; 16th Mar 2022 at 11:59 pm.

17th Mar 2022, 3:38 pm	#62
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,928	Re: My time at Rank Bush Murphy Most of the T24s we saw (and they weren't anywhere near as many as the T22s!) had Toshiba tubes fitted and, guess what, they never failed. The on/off switch, buttons and tuner were a different story. As I said earlier, the only Toshiba part to fail for us was the 36k resistor feeding the sandcastle pulse to the decoder going high in value which became something of a stock fault. Going back to the OP, I am surprised the T20 series was developed by a different team to the Z718. The chassis, frame timebase and, as said above, the IF/decoder were all very similar. It's like a manager gave the team a Z718 and asked them to make it work a 20AX tube. And what's with the Z prefix? A680, 774, 816, 823 - then the Z arrives, just for the 718 and Z179. Perhaps should have been Z719 - would have made more sense. __________________ Glyn www.gdelectronics.wales

17th Mar 2022, 4:13 pm	#64
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: My time at Rank Bush Murphy The tuner in the first production C2290/24E Toshiba used the Rank tuner but was soon replaced by a Toshiba unit. I can't remember replacing the ON/OFF switch. I guess it was similar to the one fitted in the Dixons own brand model, I can't remember the name, with a Toshiba 'kit' chassis fitted from a much earlier model. I certainly replaced a lot of those! John.

17th Mar 2022, 6:06 pm	#66
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: My time at Rank Bush Murphy CONTEC That was the brand with the TOSHIBA kit chassis. Very reliable. I think RBM used the SABA chassis in their first colour portables. Not bad but it seemed to be plagued with shorting diodes. J.

17th Mar 2022, 8:02 pm	#67
slidertogrid Octode Join Date: Apr 2005 Location: Peterborough, Cambridgeshire, UK. Posts: 1,898	Re: My time at Rank Bush Murphy Wasn't there a set badged Triumph that was the same as the T24? I found one of those Contec portables near the skip at the house clearance place that I have had a few sets from, the on off switch was knackered on that set, it wouldn't latch. I wish I had saved it now but in my defence it had got very wet! __________________ The rotation of the earth really makes my day...

17th Mar 2022, 8:45 pm	#68
MickMcmichael Pentode Join Date: Mar 2009 Location: Peterborough, Cambridgeshire, UK. Posts: 196	Re: My time at Rank Bush Murphy Yes Rich. Triumph was the name used by Curry's rentals back in the 80's. I'd never heard of them until Visionhire bought Curry's rentals out around 1985. All of a sudden we had a deluge of Triumphs and Grundigs coming in off rental as well as all the extra other work we'd just taken on as Serviscope. I believe there were some T24's amongst them. Also lots of Orions badged Triumph too.

20th Mar 2022, 12:14 pm	#70
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: My time at Rank Bush Murphy I seem to recall that RBM marketed a 110 degree 26" Delta gun receiver possibly of German origin. I only came across a single example but I no doubt have the manual due to RBM forwarding a manual for every new release together with a copy of 'Service Skill' It will take too long to find it! John

20th Mar 2022, 3:20 pm	#71
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,928	Re: My time at Rank Bush Murphy I think that was the Z179. I also thought it was imported until I looked inside and saw an SL901 and SL918, and the manual confirmed it was a British TV. Hinge down PCB looking fairly conventional apart from the decoder. Used an A66-140X 110 degree CRT. __________________ Glyn www.gdelectronics.wales

21st Mar 2022, 2:18 pm	#72
1955APREN Hexode Join Date: Nov 2010 Location: Market Drayton, Shropshire, UK. Posts: 487	Re: My time at Rank Bush Murphy I did not like Z718 as field eng lots of complaints regarding not starting from cold, fault did not show on visits . I seem to remember that this was due line osc line driver stage start up circuit . I acquired a T24 with a triumph badge on this one was BER by our work shop staff as it had seen a very large voltage going in via the aerial lead the pc was blown to bits, having fitted jumper leads across all burnt up pc and fitting a new aerial socket set work fo the next 8 years till he crt went low. what a great set I loved them Derrick

23rd Mar 2022, 1:08 pm	#73
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: My time at Rank Bush Murphy Thanks Glyn. I thought a 110 degree delta existed but they were very rare. All that tooling up for a very small production run. John.

23rd Mar 2022, 2:05 pm	#74
slidertogrid Octode Join Date: Apr 2005 Location: Peterborough, Cambridgeshire, UK. Posts: 1,898	Re: My time at Rank Bush Murphy The Pye 731 series used a 110 degree delta gun tube. All that extra raster correction with it's effect on reliability and cost just to shave an inch off the depth of a set! Later on Pye realised buyers weren't bothered about slimline, just price, so they brought out the 725 with a 90 degree tube, simpler chassis less cost and (a bit) more reliable. Wasn't the G9 also 110 degree delta? Only saw a few all 26" sets I don't know if they made a 22" ? __________________ The rotation of the earth really makes my day...

23rd Mar 2022, 3:06 pm	#75
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,928	Re: My time at Rank Bush Murphy Yes - they Pye 731 drove a 26" 110 degree tube and, unusually, a 22" 110 degree as well. As you say, the 725 90 degree chassis was much better, though the bar was set pretty low... The G9 used the 110 degree delta CRT, only 26" (A66 140X) as far as I remember. 110 degree sets using this CRT were much more common on mainland Europe, with sets such as the B&O 3400, Philips K80, Tandberg CTV2, Grundig 5010 and Telefunken 711 to name just a few that made it over here (the latter I wish hadn't!). The Z179 even looked German which I assume was RBM's intention. In fact RBM were conspicuous by their absence in the 26" stakes - did they ever do one in the A823 or T20 series? If they did, I've never seen one - the old 25" sets were the largest I saw besides the Z179. __________________ Glyn www.gdelectronics.wales

23rd Mar 2022, 4:04 pm	#76
slidertogrid Octode Join Date: Apr 2005 Location: Peterborough, Cambridgeshire, UK. Posts: 1,898	Re: My time at Rank Bush Murphy Now you come to mention it I can't remember a 26" A823 or T20 either . 25 " early A823 yes, they must have made one though as the Zarach Tv mentioned in the other thread seems to have used a 26" A823 as the donor set. Maybe they were made but didn't sell well. Another anomaly that springs to mind was the Ferguson TX stereo TX10 or 100 Thorn never made a 26" set for retail, only for the rental outlets badged as Baird or DER. When I think about it in the 70s and early 80s we didn't sell that many 26" sets compared to 20 and 22". The thirst for bigger screens seems to have come along a bit later on. That said most of our customers didn't have large houses with large rooms! __________________ The rotation of the earth really makes my day...

23rd Mar 2022, 5:31 pm	#77
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: My time at Rank Bush Murphy These cards from the 1-1-70 service manual show that there was a 26" version made and a number with the later varicap tuner version. I had never thought about it but I can't ever remember seeing one! I had a 26" version of the Z718 complete with Prestel terminal. It worked quite well but unfortunately like so many other interesting receivers were skipped when I closed the shop in 2003. Attached Thumbnails

23rd Mar 2022, 9:15 pm	#78
line sync Heptode Join Date: Sep 2009 Location: Kinver, Staffordshire, UK. Posts: 635	Re: My time at Rank Bush Murphy There were quite a few 26 models fitted with the A823 chassis , i owned a 26" murphy with folding doors years ago. It would be interesting to here if dave can tell us any think about the A823 chassis ? Robin

23rd Mar 2022, 9:30 pm	#79
davidh1041 Pentode Join Date: Mar 2009 Location: Norwich, Norfolk, UK. Posts: 228	Re: My time at Rank Bush Murphy Have to say i have really enjoyed this thread, very interesting. Here is a picture of my 26" Bush A823 Attached Thumbnails

23rd Mar 2022, 10:00 pm	#80
neil29 Heptode Join Date: Dec 2004 Location: Newport, Gwent, UK. Posts: 962	Re: My time at Rank Bush Murphy I've got a Bush CTV197C and a Murphy CV2612C and a 26" Z718. and several years back i did have a 26" T22 that i broke up unfortunately. Cheers Neil.