7th Sep 2014, 10:29 pm | #161 |
Heptode
Join Date: Jan 2008
Location: Oslo, Norway.
Posts: 632
|
Re: Favourite Colour Televisions.
|
7th Sep 2014, 10:33 pm | #162 | |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Favourite Colour Televisions.
Quote:
Your set was made in the Rank-Toshiba factory at Ernesettle, Plymouth. The works closed in 2009. DFWB. |
|
7th Sep 2014, 11:46 pm | #163 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,580
|
Re: Favourite Colour Televisions.
Hi.
Thinking back, the Rank T24 (20" 90 degree PIL) chassis was exceptionally reliable and this was clearly a Toshiba offering. I wonder if Toshiba used it in their sets as well or was it only fitted to Bush and Murphy models? By comparison, the T20 was pretty awful reliabilty wise but wasn't too bad for servicing. Picture quality was only mediocre as well. A few of these sets I serviced had suffered from resistor troubles, EW modulator diodes going s/c, power supply failures, connector problems and dry joints. Tripler failure was fairly common and the LOPT wasn't all that reliable. One stock fault I recall was a 910 Ohm resistor in a low voltage regulator circuit on the timebase board, this was underrated and would often go o/c. I did like the stand alone 200V SMPS which wasn't line synchronous as in the Philips K30 etc so was easier to repair. Things did improve a little with the T22, this had a SAWF in the vision IF stages as opposed to individual bandpass filter coils as in the T20. The 30AX T26 wasn't bad either but I didn't come across many of these. I think this must have been Rank's last British colour chassis. I did like the Z718 especially with the 18" PIL tube, that was a really good performer. Regards Symon. |
8th Sep 2014, 1:02 am | #164 | |
Hexode
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
Posts: 280
|
Re: Favourite Colour Televisions.
Quote:
The Toshiba was a revelation after years of watching faulty colour on a Bush A823.
__________________
Classic TV Show Theme Tunes |
|
8th Sep 2014, 9:53 am | #165 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Favourite Colour Televisions.
The Rank-Toshiba T24 chassis was used in the 20" CRT Toshiba C2090B and C2095B TVs. Also a Bush set, the BC7200, another 20" set.
That's right, the T20 was rubbish. I was lumbered with dozens of them in my rental fleet. The T22 was a bit better and with the introduction of the T26 in 1980 most of the reliability issues had been addressed. But, it was too late, in 1980 Rank Radio International closed down for good. Toshiba took over the factory. DFWB. |
8th Sep 2014, 12:29 pm | #166 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
|
Re: Favourite Colour Televisions.
Was the Bush T20 chassis the one with the one ohm resistor in the base circuit of the line output transistor that when high and damaged the transistor?
|
8th Sep 2014, 12:58 pm | #167 | |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Favourite Colour Televisions.
Quote:
I've still got a few bits and pieces for the T20 including the 910 ohm resistor that often failed in the start up circuit. A common fault was the burn up of the scan coil plug. Might still have one in stock. DFWB. Last edited by FERNSEH; 8th Sep 2014 at 1:07 pm. |
|
8th Sep 2014, 1:25 pm | #168 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
|
Re: Favourite Colour Televisions.
hi David,
It is the chassis I remember, I did not think much of it, seems others have the same opinion. I had similar problems with the tripler as well, no memories of the startup resistor but the sets were quite new when I changed careers. Frank |
8th Sep 2014, 1:44 pm | #169 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Favourite Colour Televisions.
Hi Frank,
The T20 was all right when new although the 20AX picture was not the best. The problem with all sets that employed the 20AX CRT was the high scanning currents demanded from the timebase and power supply. Lots of heat followed by component failures. There was an electrolytic capacitor in the start-up that often dried up. Of course when one became familiar with the all the stock faults it was rarely necessary to return the set to workshop. I've still got the special box for the replacement panels. Now if you are asking about my favourite picture display system it has to be the 30AX. Best CRT ever! DFWB. |
9th Sep 2014, 9:36 am | #170 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
|
Re: Favourite Colour Televisions.
The museum at Dulwich has just aquired a 'BUSH' BC7200 employing the Toshiba 2090 chassis. It required no attention what so ever and produces a picture as good as new. It has never been touched in 34 years. It's about as good as it gets. I will attempt to count the number of Toshiba 2090/2290 receivers I sold during my days at the shop. I have my old stock books in a 'safe place'...I never had a service call related to receiver breakdown to any of them. The Toshiba version was very smart with a silver front and there was a remote control version, C2095 etc. .Incredible. Happy days! Regards, John.
|
12th Sep 2014, 2:08 pm | #171 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,927
|
Re: Favourite Colour Televisions.
Hi
The only faults I had on the T24s were the 36k (I think) resistor that fed pulses to the decoder (no colour) and the tuner and on/off swiches - the latter both Rank parts! They looked like the later T22s and it was always a pleasant surprise to see the T24 lurking in there. The T26 was actually pretty good, thaough the 30AX CRTs fitted to them had a very short life. Frame chips and triplers were the favourites there. As said above, the stand-alone power supply was very good and could easily be removed and worked on. They were handy as a test supply as well - the T20 giving 200v and the T26 160v if I remember. The well-liked Toshibas also appeared in a more basic cabinet under the Triumph (Currys) banner. Very reliable with just the mains switch/volume control causing bother - doubtless not a Toshiba part! Wasn't there also a Toshiba 22" set with an LED clock on the front? And now I have a Toshiba LCD on the bench causing me grief - oh look, it's a Vestel... Glyn |