• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Tube amps with tv tubes

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Hello
I have a question and maybe a favor to ask
Who here uses or had any tv tubes ?
Don’t some tube amps use tv tubes ?
Reason why am asking for some free ( donated ) TV tubes, is I acquired a mint ,technicians vacuum tube rejuvenator , for TV tubes. And is like to give it a try to see how it works.
It’s made by B&K , model 465 CRT tester
So if anyone can help, I would really appreciate it. Please send me a message or post openly about your knowledge involving TV vacuum tubes in an audio circuit of amplifiers
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Yes, it can do some amount of "rejuvenating" of CRTs. It won't work with sweep tubes or other tubes that would be useful in an audio amp.

Still, CRT testers can come in handy every now and then, especially if they can do the type of CRT found in test equipment.
 
Thats an early version of the BK tube tester for B/W TV,s I have the later multiplex automatic version with three dials for color TV.
It uses pulse techniques that overcome the manual overzealous stripping of the cathode of TV CRT therebye rendering the tube as useless .


I know what the big question here will be -can it renovate a big output pentode IF you modify the connections --answer ----yes with a big stipulation ---once you try it once and the cathode is so rotten to begin with and you don't see a rise in emission------DO NOT TRY IT AGAIN !!
You have been warned !

Do NOT leave it running for long its a amplifier tube you are renovating not a CRT cathode.



I must say in all honesty I really admire this piece of American electronic engineering , I have the instructions & circuit diagram somewhere ,many UK television shops had one that's where I got mine .


Spares are available online even some sold as spares I converted many bases the same way I converted new bases for my AVO VCM MK4 but this time attached to plug in wiring to the unit.
 
I have used (still do) tons of "Radio" and "TV" tubes to make Guitar amps with excellent results.
Sweep tubes, mainly 6DQ6, EL36 , etc. for power; pentodes such as EF184, simple or double triodes such as 6AV6, 6CG7, E/P CC 188/189, etc.

If it has cathode, grid and plate, and is vacuum sealed, it will do useful work; you just have to load and bias it properly.

No, they won´t straight pull into Fender/Marshall/VOX circuits, so what?

Like Hercule Poirot would say: "just use the little grey cells!!!"

Will I send some your way?
No way!!!, not junkbin stuff for me but very useful fellows, I credit them for what they do :D

A Brazilian friend uses nothing but TV tubes to make his cool sounding amps:

FURADA! W.Fillies Wizard 238 - YouTube
Amplificador com valvulas de tv 6BL7,,EF184,,6BZ6,,6SN7,,6C10 e 5U4
 
The OP's appliance was exclusively dedicate to 'regenerate' CRT cathodes, hence inflating some more hours of life into this most costly component. After applying an elevated heater voltage, a heavy current surge was applied between the cathode and the modulator electrode to blast off dead zones from the coated surface.
Even in the tube heydays no serviceman would have tinkered with regenerating any other tube this way, as the control grid would not have survived the current surge.
@kodabmx: The JEDEC equivalent of the EL509 is called 6KG6.
Best regards!
 
Arent you thinking of earlier ( cheaper ) CRT renovators / rejuvenators like Beltron (USA ) which applied =300 volts to the cathode and first grid as LONG as the renovate button was held DOWN ?


BK 467 does not work that way it uses a small capacitor to discharge for a computed set period in a modulated/ pulsing action its a lot more technical than you think . yes the old ones "blasted " off the cathode coating AND the cathode if you used a lead finger --times change.
 
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For European viewers US terminology Magnoval is known here as=B9D conforming to the Pro-Electron nomenclature ( Standard,s Body ) I can see the point of Kodabmx,s complaint I was not alone in complaining about the engineering imbalance of a very large tube having small steel pins with the only reinforcement being the glass base ,it got worse with the even heaver later versions used in color TV,s .
 
Well, you were supposed to put the tube in the TV, then leave it alone till the deflection circuit goes out and you no longer get high voltage for the CRT. When it just goes dark that’s the first thing you check, and the usual culprit. Us DiY audio guys are constantly swapping things in and out, which doesn’t make life easy for compactrons.

In my experience with tube TVs, it was usually the *vertical* sweep that went out first, resulting in a bright horizontal line on the screen. Don’t know why we couldn’t keep vertical sweeps running longer.
 
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