[ARC5] Annual "Real Bench Challenge"

[David Rossetti]

I’m sorry to say, my bench is currently a little off topic. 

 



 

What you see is a recent purchase off of eBay, a Tektronix 576 curve tracer. Got it cheap (relatively) in that it was untested. Fixed a few minor issues, calibrated it, and she is now working fine. Here, I am running curve traces on a pair of 6L6 tubes. The filament and screen voltage is supplied by the Heathkit power supply. I connect the tester emitter to the tube cathodes. The swept 350 voltage collector output is connected to the tube plates. The tester base output, in two volt inverted (negative) steps, feeds the tube grid. Curves are quite standard for this tube. The top sweep is at 0 grid volts, the second at -2 volts, etc.. Throwing the switch (not illustrated) swaps the screen, grid, and plate voltages from one tube to the other. As it turns out the two tubes were not very well matched.

 

Somewhere nearby are the schematics for an R-24 broadcast band receiver, perhaps my next restoration project, just to prove I really am an ARC-5er.

 

Dave Rossetti

 

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