Unknown metal-mazda valve

ID: 420813
? Unknown metal-mazda valve 
17.Jul.17 18:09
33

Nicolaas van Dijk (CR)
Articles: 43
Count of Thanks: 5
Nicolaas van Dijk

I have a valve, clearly an indirected heated triode with a 4 pin European base and two side contacts. The barnd says MetalMazda with a common M.

I can´t read the complete number, what I can read is BV?604.

Also stated at the ballon is 2.5 V and 150 V

The interior is a round anode and grid like the A415 with approx. the same dimension, but a indirected heated cathode

Anyone an idea?

Regards

Nico

 

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 2
Unknown metal-mazda valve 
17.Jul.17 23:18
33 from 1472

Wolfgang Holtmann (NL)
Editor
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Wolfgang Holtmann

Hello

I think the correct type is BW604.
It is indeed an indirectly heated triode for AC supply via the side contacts.

This was done to replace the old directly heated triodes (by a storage battery) in a wireless set.
You have simply to add a transformer fed from the mains.

Kind regards.

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 3
Unknown metal-mazda valve 
17.Jul.17 23:40
39 from 1472

Nicolaas van Dijk (CR)
Articles: 43
Count of Thanks: 5
Nicolaas van Dijk

So the question mark is the other half of the W!!

Thanks a lot for the info Wolfgang, highly appreciated. I will mark the tube as such

I saw it is from 1928, nice

Kind regards

Nico

 

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