|
Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
|
Thread Tools |
11th May 2006, 10:57 am | #1 |
Octode
Join Date: Oct 2005
Location: Wimborne, Dorset, UK.
Posts: 1,407
|
CTV Tubes
Greetings,
Just a quick question, Does anyone know when the phosphors on CTV tubes changed from being round to rectangular? It's just one of those pointless questions I felt I needed the answer to. Kind regards Lee
__________________
Lee |
11th May 2006, 11:56 am | #2 |
Octode
Join Date: Nov 2003
Location: Bath, Somerset, UK.
Posts: 1,805
|
Re: CTV Tubes
The original Delta "triple dot" formation gave way to the "in line" formation with the introduction of the Philips "AX" series tube around 1974. Although the Sony Trinitron system with "in line" configuration arrived in around 1970, this was a different type of system entirely.
Neil |
11th May 2006, 11:04 pm | #3 |
Octode
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,898
|
Re: CTV Tubes
The Thorn 9000 was the first set I saw with a PIL (Precision in line) tube, this was where the phospher was arranged in coloured rectangles, previous tubes were delta gun where the phosphers were arranged in triangles .I think the 9000 dates to around 1973/4.
I remember the early pil tubes didnt last long, Hitachi had a real problem with a directly heated cathode pil tube they lasted on avarage 10 months! but to give them their due Hitachi replaced every one even when the sets were out of gurantee, cant see that happening nowdays |
12th May 2006, 5:40 pm | #4 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,921
|
Re: CTV Tubes
Hi
Yes - the first non-trinitron tube was in the Thorn 9000, closely followed by the (much longer lasting) ITT CVC20, and a most odd 110 degree 20" pil tube in the Rediffusion Mk3 which seemed to last for ever! The 20" seemed (at first anyway) to be much longer-lasting than the larger sizes. |
12th May 2006, 10:03 pm | #5 |
Octode
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,898
|
Re: CTV Tubes
The Decca 80 used a early pil tube that was notorious for going flat after a few years, I think the heaters were underun from new and many sets were looking sick at 3/4 years old, the practice with these (rental) sets was to unsolder one of the wires on the lopt heater winding pass it throught the core and resolder it! this added about 1/2 a turn to the heater winding and in some cases gave the sets another 5 years! happy days! Dont ask what we did to the G11! the "heater mod " we devised for that would make Len Briggs Turn in his grave!
|
13th May 2006, 12:19 am | #6 | |
Nonode
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
|
Re: CTV Tubes
Quote:
Regards,
__________________
Brian |
|
15th May 2006, 12:02 am | #7 |
Octode
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,898
|
Re: CTV Tubes
We devised a terrible "heater mod" for the G11 ,which I hasten to add were rental sets towards the end of there usefull life at the time, first you cut the print between the heater fuse holder and the lopt, then you soldered a wire to the lopt pin , passed it through a convienient hole in the line panel( near the lopt) passed it through the core of the lopt and soldered it to the fuse holder, the fuse was then removed and a resistor soldered across the fuse holder on the back of the print, the it was a 5watt ww and the value varied from 3R3 to 1R5 depending on how flat the tube was, if it was really duff you could always refit the fuse!this usually brought the tubes back to life for a while .PIL tubes never seemd to reactivate well , the old delta gun tubes would boost and last, but "bump " a pil and it usually killed it! hence the heater mod ! Happy days!!
|
15th May 2006, 10:05 pm | #8 | |
Nonode
Join Date: Jun 2005
Location: Western Lake District, Cumbria (CA20) - UK
Posts: 2,136
|
Re: CTV Tubes
Quote:
(I always had a soft spot for the G11 despite the dry joints). as for rejuvenating tubes I found it made a difference which type of tester / rejuvenator you used. The most effective for me was the Leader. Mine was bought secondhand from Stewarts of Reading and worked well on most tubes, even PIls if caught early enough. Those were the days! Regards,
__________________
Brian |
|