[Boatanchors] Fusing secondaries

[john]

I'd suggest doing what is done in power amps...use a low resistance carbon comp resistor as a fuse. Standard 3AG fuses may not clear under secondary voltages (they're certainly not designed to).  Use of the properly sized 5 ohm or less resistor in the secondary B+ line is what is done in many linears.  This is done mostly to protect the tubes from damage under glitch conditions, which may be what you have in mind?

John K5MO