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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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27th Feb 2013, 11:41 pm | #21 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,562
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Re: Is this tube beyond redemption?
Hi John.
Do you have a copy of the circuit and article of 'Bertha' from Practical Television? Regards Symon. |
28th Feb 2013, 9:35 am | #22 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
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Re: Is this tube beyond redemption?
I did upload it some while back. It may be in the archive. If not let me know and I will post again. DECEMBER 1957. There is a picture of it on the front cover. J.
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28th Feb 2013, 10:49 am | #23 |
Retired Dormant Member
Join Date: Jan 2007
Location: Westbury, Wiltshire, UK.
Posts: 2,451
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Re: Is this tube beyond redemption?
I'm not sure if this is on topic or not but some while back I made up an adapter using an old valve base so that I could boost an ECL80 valve with my tube kicker. It worked fine.
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28th Feb 2013, 11:24 am | #24 |
Hexode
Join Date: Jan 2013
Location: Ă…lesund, Norway
Posts: 361
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Re: Is this tube beyond redemption?
I was looking for any info about the Bertha tube reforming equipment and came across these postings:
https://www.vintage-radio.net/forum/...ad.php?t=25346 and this attachment: https://www.vintage-radio.net/forum/...4&d=1202648559 Hope this helps and is not to far off topic. Tony |
28th Feb 2013, 2:21 pm | #25 | |
Hexode
Join Date: Feb 2011
Location: Gloucestershire, UK.
Posts: 376
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Re: Is this tube beyond redemption?
Quote:
Last edited by Andy Doz; 28th Feb 2013 at 2:34 pm. |
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28th Feb 2013, 2:46 pm | #26 |
Heptode
Join Date: Feb 2007
Location: West London, UK.
Posts: 865
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Re: Is this tube beyond redemption?
The December 1952 Television magazine also has a CRT restorer circuit.
John |
28th Feb 2013, 6:35 pm | #27 | ||
Hexode
Join Date: Jan 2013
Location: Ă…lesund, Norway
Posts: 361
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Re: Is this tube beyond redemption?
Quote:
Tony |
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28th Feb 2013, 7:50 pm | #28 |
No Longer a Member
Join Date: Dec 2007
Location: Bristol, Avon, UK.
Posts: 184
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Re: Is this tube beyond redemption?
There were many circuits that operated directly off the mains, dont recall any accidents.I can remember charging batteries by connected across the terminals of a light switch,think how scary this is, also at the bench our continuity tester was a 60w lamp and a 240v mains,if you got your fingers in the way,it was not very pleasant!
The fact is that people are not so intelligent today, and often dont understand safety,or have any idea of what can happen. more people are getting involved with electrics,often modern H&S rules, which in theory are good,is also preventing people from learning, ie,take the 13a plug many adults can not wire a plug,now that everything comes with plug fitted! Safety, after all is down to the user, and his intelligence. Now back to the circuit, it may or not work,more kill or cure, ie it could strip the cathode, Tube reactivaters used a similar idea with increased cathode temperature, this would clean up the cathode. |
28th Feb 2013, 9:03 pm | #29 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
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Re: Is this tube beyond redemption?
The circuit published By Mr L Cox does work very well and of course care must be taken with the direct mains connection but anyone nervous of this arrangement should not be working with vintage television receivers. I would be happier with a 5W nightlight lamp rather than a 15W but I have a similar unit and it does the trick without overkill. An old selenium rectifier [it can be a discarded one due to low output] works very much better than a silicon diode as it tends to have a 'sponge' effect with less clout. J.
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28th Feb 2013, 9:03 pm | #30 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,562
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Re: Is this tube beyond redemption?
Quote:
I couldn't find the article on your CRT tester 'Bertha' but lo and behold, I found another box of Practical Television magazines in my loft. Luckily, the December 1957 issue was in there. That looks a good little tester to build and will be looking forward to trying out the circuit. As you point out, many rejuvenators are too brutal on reactivation, and from my own experience over the last thirty years, have found that boosting doesn't usually last that long. This is probably due to the emissive surface of the cathode being stripped off because of a crude reactivation process. Regards Symon |
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2nd Mar 2013, 10:00 pm | #31 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
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Re: Is this tube beyond redemption?
Hello Simon,
Well done! I would certainly recommend the use of an old selenium rectifier. It's tempting to use a silicon diode for HT rectification but a worn old finned rectifier appears to be more suitable. J. |
3rd Mar 2013, 3:40 pm | #32 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,562
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Re: Is this tube beyond redemption?
Hi John.
Thanks for the tip re the selenium rectifiers, and I do have one or two knocking around somewhere. The only other item to be problematic is the transformer. From the photo on the first page of the article, it clearly is a Radiospares part and I can just make out the letters 'ersal', probably universal. The rectifiers are obscuring the word. Maybe I could use two separate transformers ie one for the heaters and the other for the HT supply. Regards Symon. |
16th Mar 2013, 8:52 pm | #33 |
Pentode
Join Date: Mar 2006
Location: Pontypool, South Wales, UK.
Posts: 140
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Re: Is this tube beyond redemption?
No success with the tube I'm afraid, despite an attempted reactivation using a device built to the circuit linked above, and then with a B&K 467, eventually raising the voltage heater til the filament gave up the ghost. So I am in the market for an Emiscope TA-10 tube, or perhaps a re-gun, if these CRT's can be done. Is the guy in France still active?
Jerry |