Soviet Super Transistor


The P601 I isn't the world's best transistor, and it wasn't even in 1973 when it was manufactured.

Hign Tech on Clay Feet

Soviet transistor, sideA Lithuanian friend of mine gave me a fantastic freak of a semiconductor. It came straight from the soviet semiconductor forges. Its operating specifications are strange, to say the least. It has a maximum operating temperature of 60 degrees Celsius, that would indicate it's a germanium transistor, but its UBEmax of 0.7 volts shows it's all about silicon.

Soviet data sheet, frontThe data sheet isn't very informative either. The semiconductor material isn't specified, nor is the manufacturer, and neither do we know if it's a PNP or an NPN device. Perhaps it was a state secret? An expert I consulted thought that perhaps it was made out of selenium! (Stalinium?) I presume it is germanium, but with very low doping levels, which results in the high base bias voltage and the enormous saturation voltage. The UCEsat is a fantastic 2 volts at an IC of 0.5 A, resulting in a whole watt of power dissipation at saturation. Maximum power dissipation mounted on cooler is a full 3 watts.

A typical western transistor in TO-3 can from the same time, which is what is closest to this Soviet can, should dissipate at least 100 watts, with an UCEsat of no more than 0.1 volt. This one manages a full 25 volts, but not faster than 1 MHz, because then the amplification is down to 2. Minimum operating temperature is a hefty -50 degrees Celsius, rather unusual, until one realises that the Red Army must be able to work in Siberia too. Although not for very long...

Don't sit around

Soviet transistor, topMaximum storage time is 6 years (and you are specially instructed to check the manufacturing date and start counting from then), which indicates they either didn't know how to passivate the chip, or had some problems with the hermetic sealing of the package. It is not guaranteed to operate for more than 10,000 hours (1.1 year), and when the transistor was taken off line after the 10,000 hours you were requested to send back the warranty slip and tell how things worked. As this article was written in 1999, my device from 1973 would be broken already. Russian transistor salesmen had to be fast.

If you're not completely satisfied...

At the end is the “Complaints” section, which you can fill out if the transistor breaks, so you can send it back and get a new one; a detail you definitely won't find on any western data sheet. Either they were not at all sure if the design would work, or it was just so bad they had to implement some sort of routine for complaints. Perhaps the Red Army would go bonkers otherwise.

Readable, with difficulty

Soviet data sheet, backThe first page of the data sheet has been image enhanced for you to be able to read it, but to let you experience the true junkiness, the crappy printing quality and the bad paper of a real Soviet data sheet, the second page has been left with its original colours. Note that the whole data sheet is typeset in Cyrillic type, whereas the formulae are set with roman type!

My, my, Sovietskij setskij didn't work for longer than 6 years.

Main Data





P601 I


Doesn't say

Maximum collector-emitter voltage



Maximum power dissipation



Maximum collector current



Saturation voltage (@ IC= 0.5A)



Amplification factor  

20 - 250

Operating temperature range



Maximum operating time


10 000

Maximum storage time




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