Unknown black metal "tube" ST-4, International Rectifier

I have failed to find any information about a black metal tube with American UX 4-pin base.

The tube is heavier than normal electron tube and my best guess is

that it is not an electron tube at all, maybe a selenium rectifier.

 

The tube is made by International Rectifier and all markings are visible on picture below.

ST-4 K-1 INTERNATIONAL RECTIFIER CORP. EL SECUNDO. CALIF.

I would be very gratefull if somebody could provide any additional information about this tube.

Thank You

 

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...looks like it could be an early 'solid-state' substitute for a rectifier tube such as a type 80 (UX-280) or similar.  It probably does contain two selenium rectifiers (it's probably too old for silicon) going from each large pin to each small pin, and a resistor across the two large pins to replace the original tube heater.  There could be other things in there as well, for inrush current limiting, etc.

...that's MY best guess...my personal knowledge of radios doesn't go far enough back to be intimately familiar with tubes like the 80, but I do know that solid-state replacements for rectifier and other types of tubes have been around for quite a while (and still are); this may very well be an older one of those... 

 

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Yes - correct! It is a silicon rectifier assembly with a rating of 1600 volts piv and a mean current of 750mA. It is equivalent to the 1N2634.  This was a substitute for the 80, 82, 83, 83V, and 5Z3.

A range was available which also covered the octal tubes. 

For example the ST-7A (1N2637) is a 866 replacement.

Care is always needed in replacing as the voltage drop is lower than in the tube and it is uncertain what series resistance is included in the unit.   Clearly this depends on the current drawn and the application.

I think that we can include this as a tube and I shall add it as ST-4 with any known details.  Please upload picture.  Thank you for bringing this in.

Regards,

Roy

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Hello Roy,

thanks for your response. I just uploaded a picture of ST-4.

BR

Juhani

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