Re: Repairing my Tektronix 454 oscilloscope need some advice

 

Hi Chuck,

You are very right about the importance of the diode recovery time. The specification on Amazon for this cheapy diode is Trr = 100 nS maximum. Other "fast" HV diodes specify 60 or 70 nS, not a big difference.
At 50 kHz the period of the rectified sine wave is 20 mS, 200 times longer than the Trr. During these 100nS the peak of the sine wave will barely comes down, so the operation should be safe. Indeed when I installed these diodes the efficiency of the supply increased, and it behaved correctly.

- Ernesto

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