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Will heat and long age cause failure to germanium diode? It looks weak!

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Willen

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I can see clearly there is a small spring wire connected to small germenium chip. If I soldered the diode more than two or three, I guessed cause of this heat the spring wire will loss its spring feature and will not work. Also after 15 or 20 or 30 years it might not work due to its weak design (spring system). Am I right?

Today I collected 10ths of very old germenium diodes from very old radios of 1960s or 70s. Suspecting their functionality because of its long age. Add something please!
 

kubeek

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I think that the culprit is usually the germanium junction and not the wire, germanium decvices were very sensitive to temperature.
 

audioguru

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Most of us have not used a germanium diode for at least 45 years so we do not know if they are still operational today.
Build a modern circuit instead.
 

Willen

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Ancient mechanism is so interesting :) where i can see each operation and can feel it. So :)
 

Nigel Goodwin

Super Moderator
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Most of us have not used a germanium diode for at least 45 years so we do not know if they are still operational today.
Build a modern circuit instead.
You still need a germanium diode even today, for signal rectification - particularly in a crystal type set.

However, more in keeping with this thread, germanium devices were EXTREMELY heat sensitive during soldering, and easily destroyed if you take too long. The advent of silicon cured this problem, with silicon being much less sensitive to heat during soldering.
 

unclejed613

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not sure about the diodes, but i do know from a NASA study, that many germanium transistors in storage as spares were found to have failed, not due to any weakness in the semiconductor material, but because the tin plating inside the transistor case grew tin whiskers over the years. if the same tin plating were used inside a diode, it could cause problems, but many of the germanium diodes i've seen actually used gold plating on most of the exposed internal parts.
 

dr pepper

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I have a couple of 60's car radios by mopar containing rca germanium transistors, rca made a batch, a very large batch of 4 pin trannys where the sticky goop inside the transistor etches away (slowy over 40 years) at the junction and destroys it.
That is just what I heard, the above description might be the actual reason, I wonder if bulb bopping would fix ingrowing whiskers?

Vibration can also cause failiure, the whisker lets go, but I think you'd need to be severe to do that.

So long as the junction temp doesnt go over the max specified in the datasheet it should work for years.

I'm with nige, you can still get ge junction diodes for rectification, switching and probably a load of other uses.
 

schmitt trigger

Well-Known Member
"you can still get ge junction diodes for rectification, "

Where can one get a junction Ge diode suitable for rectification?

There used to be a company called Germanium Power Devices, but they stopped making plain Ge transistors and diodes, and focused on other exotic applications.
 
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