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When vacuum tubes go bad .....


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... they can get very hot. Plate voltage is often over 350 volts DC.

I was browsing thru some old pic files and found these pics of a pair of 6CA7 power tubes on the verge of meltdown. My nephew brought over this Traynor amp, vintage 1973. It was behaving badly, sometimes, not all the time. Thumping it with a fist wasn't working anymore. [:)]

It was fun for a few days, because the problem was intermittent. It sat on the bench for a whole day and did nothing. then when I flipped the chassis over one time, I got this redplate reaction. And captured it for my files. A new matched set of Russian power tubes was all it needed.

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tn_2011828164012_redplate2.jpg

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tn_2011828164045_redplate3.jpg

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Apparently the reaction was strong enough to affect the autofocus on your camera.

I think I turned off the flash for those shots, so with a cheap camera, the longer exposure makes a fuzzy pic. I'm obviously no photographer.

Les, that Philco Admiral, thanks, Marc, has some value to somebody. The round picture tube makes it collectable. No, thanks, I'm not interested. [:)]

A few years back, it was a fad to convert the old Futura TV's into computer monitors. Sacrilege!

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Les, that Philco has some value to somebody. The round picture tube makes it collectable. No, thanks, I'm not interested. [:)]

A few years back, it was a fad to convert the old Futura TV's into computer monitors. Sacrilege!

I thought it was an Admiral. The 2nd one an RCA. Les?

Marc

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