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Old 20th May 2014, 9:13 pm   #1
Miguel Lopez
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Join Date: Dec 2011
Location: Mayabeque, Cuba
Posts: 617
Default D226 Diode (Silicon or Germanium)

Hello

Since I started to enjoy electronics, I have always use the D226 Soviet diode.

It has been available in Cuba for years as almost all the vintage Soviet equipment used it. I have always thought that it was a Silicon diode, but now I read on radiomuseum.org that it is a Germanium diode
http://www.radiomuseum.org/tubes/tube_d226.html

So I made some test, cause I have always seen a voltage drop of 0.6 to 0.8 volts on this kind of diodes.

I measure the voltage drop as I passed a current throught it. With 5mA it dropped 0,55V and with 40mA, it dropped 0,8V. It behaves as a Silicon diode but with some differences.

I did the same test wit a KD202 diode (which I know is a Silicon diode, due to the prefix K [кремний]) and it dropped between 0,58 and 0,65V with the same variation of current.

AFAIK, Germanium P-N junctions drop 0,2 to 0,3V when forward biased.

So, I think there are several possibilities here:

1.) It is a Silicon diode.
2.) It is a special kind of Germanium diode
3.) It is three Germanium diodes in series.

Any help about this?

Thanks in advance
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