RT655, RT656, RT636, RT643

I have listed these tubes as "battery". But all of these tubes has a strange low filament voltage of 0.6 Volt.The firstPhilips AC tube was the C0805 in 1926. As the designation says, the filament voltage of this tube was 0.8 Volt. This was also a direct heated tube.

Could the RT636, RT643, RT655 and RT656 be early AC types?

Peter den Boer

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Hello Peter,

in the event that you have this «Radiotechnique» advertisement sheet (with these tubes in yellow) in complete condition, from which you did cut-out the data of the individual tubes, - the answer to your question might probably be found there.

If so, then please post it here completely, in order that someone can translate it.

Best Regards,

Jacob

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Well, my French is not that good, but the problem is that I did not look good. At the top of the attached page is printed  ... sur le réseau alternatif. Which means that these tubes are indeed AC tubes.

I also overlooked the note at the end of the page. Hier is written that these tubes have two extra side terminals. This is usual an alternative way to connect the filaments.

Sorry for the inconveniance. I will try to be more carefull.

• RT655, RT656, RT636, RT643 (181 KB)

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Hello Peter,

thank you for posting this valuable document. It's just a I expected, «fonctionnant directement sur le réseau alternatif» means something like «works directly on AC voltage».

As for this strange filament voltage of 0.6 Volt, there might very little else to be expected.

Btw., your attached data file RT636 has no contend =(0 kb), though the first data file RT655 has all it takes.

Best Regards, Jacob

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Hello Jacob,

Yes there are listed two 0 kb files. But the download failed because the filzeseizes were to big (above 200Kb). I had to reduce the number of pixels te get under 200KB and keep it readable.If you are interested, hier are the other 3 pages.

Best regards, Peter

• RT655, RT656, RT636, RT643 (188 KB)
• RT655, RT656, RT636, RT643 (188 KB)
• RT655, RT656, RT636, RT643 (194 KB)

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