Bad part can come from anywhere

[Gepetto]

The MPSA 42 is pretty damn handy...

Yes it is Lee, great device

 

[oldphaser]

Phase Linear Service Bulletin - Pin Out Changes

I ran into the problem with pin-out changes a long time ago after learning the hard way by stuffing the part in incorrectly and then taking the amplifier to Dean.
After that I always use my handy-dandy Octopus tester to make double-sure I get the pin orientation right. Whenever an old transistor comes out a replacement part goes in the correct way.

Phase Linear issued a service bulletin on the subject of "pin out changes" a number of years ago which I have included as an attachment.

Ed

 

[wattsabundant]

Use the MPSA42 or ZTX857STZ and you will not run into this problem again. There is no alternate pinout for these devices thus no confusion.

The ZTX857 is a much more robust device to boot.

The 6517 is a high voltage version of the venerable 2N3904. I used it here because it's been used for 40 years to drive an ice cube relay in the inverters at my day job. The DC link voltage on the inverters is as high as 315 volts.

 

[Bradrock]

The MPSA 42 is pretty damn handy...

They are also popular with the DIY Nixie tube crowd.

 

[laatsch55]

As a driver?

 

[Bradrock]

Yes it's one of the most popular drivers. I just started looking at Arduino starter kits & happened across the Nixie tube clock craze.
I'm definitely an old dog. Might try to learn a new trick.

 

[orange]

Clocks are nice, I always wanted the Nixies for a frequency display.