[ARC5] "Quiet" ARC-5 Keying

[Bill Cromwell]

Hi Dennis,

I have not yet applied "high voltage" switching transistors inside tube
based rigs but I have used a couple inside keyers that had to handle
grid block keying and another application that switches high current
loads on and off. All the way on and all the way off. I presume that
attention to details so as not to smoke that transistor always applies.
I am planning to start using high voltage transistors inside rigs to
turn loads on/off. I also plan to use them in voltage regulators for
tube oscillators, etc. I don't think they would work well regulating the
typical plate voltage to a pair of 6146s but - those don't need that
kind of regulation <g>. The details are more stringent in the regulator
just because the transistor does dissipate power as heat.

I don't see a fuse as being there to protect a switching transistor. I
see it there to prevent a fire if/when there is a short and a current
overload. All of my stuff is appropriately fused. I refuse to connect
power if it's not. Yes...sometimes when the fuse has self-sacrificed a
transistor died trying to protect the fuse. Both are cheap.

73,

Bill  KU8H