[Amps] Options

Peter Chadwick g3rzp at g3rzp.wanadoo.co.uk
Sun Aug 6 08:24:02 EDT 2006


Pappenfus describes a method matching tubes with varying the screen volts and having individual bias pots - in that example, 3 off 4CX250B.
It should be possible to check emission by checking contact potential with just the heater fired up. If you are quick, you won't need to run the heater for long, so won't need to blow it. Use a meter on milliamps: if they're all the same, they could all be u/s, of course.
A choke input PSU with lots of output capacity would drop the HV to around 1500. At the end of the day, it all depends on how you want to spend your time!

73
Peter G3RZP


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