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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 27th Feb 2013, 11:41 pm   #21
Philips210
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Default 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.
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Old 28th Feb 2013, 9:35 am   #22
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Default 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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Old 28th Feb 2013, 10:49 am   #23
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Default 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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Old 28th Feb 2013, 11:24 am   #24
Anthony Thomas
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Default 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
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Old 28th Feb 2013, 2:21 pm   #25
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Default Re: Is this tube beyond redemption?

Quote:
Originally Posted by Anthony Thomas View Post
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
Nice - straight across the mains. I can hear the 'elf and safety bloke whimpering in the corner from here... clutching a suicide lead .... and mumbling something about rubber mats and isolation transformers...

Last edited by Andy Doz; 28th Feb 2013 at 2:34 pm.
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Old 28th Feb 2013, 2:46 pm   #26
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Default Re: Is this tube beyond redemption?

The December 1952 Television magazine also has a CRT restorer circuit.
John
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Old 28th Feb 2013, 6:35 pm   #27
Anthony Thomas
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Default Re: Is this tube beyond redemption?

Quote:
Originally Posted by Andy Doz View Post
Quote:
Originally Posted by Anthony Thomas View Post
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
Nice - straight across the mains. I can hear the 'elf and safety bloke whimpering in the corner from here... clutching a suicide lead .... and mumbling something about rubber mats and isolation transformers...
I hear what you say Andy and wholeheartedly agree, but the idea is perhaps sound with an isolating / auto transformer in between the mains and the CRT. The circuit was drawn up by other than me and it was from on this website

Tony
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Old 28th Feb 2013, 7:50 pm   #28
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Default 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.
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Old 28th Feb 2013, 9:03 pm   #29
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Default 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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Old 28th Feb 2013, 9:03 pm   #30
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Default Re: Is this tube beyond redemption?

Quote:
Originally Posted by Heatercathodeshort View Post
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.
Hi John,

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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Old 2nd Mar 2013, 10:00 pm   #31
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Default 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.
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Old 3rd Mar 2013, 3:40 pm   #32
Philips210
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Default 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.
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Old 16th Mar 2013, 8:52 pm   #33
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Default 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
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