patters-ra: 412 - Tube 6K4

Please check the tube line up of this model. The US 6K4 linked to the model was a subminiature triode registered in the late 1945.

Many thanks,

Emilio

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It's a tetrode and the local oscillator, The 6A8 is used just as a Mixer rather than Mixer oscillator.

So maybe a Dynatron tube or Dynatron oscillator.

It's Squggle K Squiggle on schematic. :(

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Sorry Michael,

the only 6K4 listed by Lud Sibley in Tube Lore is the subminiature triode registered in 1945. Do you know the right code of this dynatron oscillator tube?

Emilio

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I don't

6K4 doesn't seem right either, the schematic looks more like 6K4 than 6K6. The tube list is obviously from the schematic (same one for all three models). I think till someone who has the physical set tells us, the tube should be marked unknown screen grid tetrode.

The only RF/IF tetrodes I know that are not KT or Beam type pentode alternatives are 5 pin I think. Nothing with a K in it.

Maybe it is a five pin tube as "pure" Tetrodes went out of fashion by the Octal Era?

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Hello,

there are three pages of the Rider's manual which are  mentioned at the model page. On page 9-6 you will find a table of voltages at the tube sockets.

For the 12-tube chassis you can find the 6K7 as the oscillator tube. So there must be an error in the schematic - if you have a close look to it (at the catode of the mentioned tube), there is a rudiment of the connection to the (not visible) g3.

Perhaps  that is what solves the riddle ?

Kind regards,

Daniel Consales

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We can remove the question mark from this thread. The solution was found by Achim Korn. The mistery tube seems to be a 6K6, also used in other models of the same manufacturer.

Many thanks to all for their contribution.

Emilio

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So the g3 is missing on the Schematic which shows a Tetrode? Possibly more than g3 is missing. Some of it doesn't entirely make sense around the Oscillator.

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