[Amps] Replacing bias string diodes in Harbach rectifier board

[Bill, W6WRT]

ORIGINAL MESSAGE:

On Tue, 10 Aug 2010 20:43:55 -0000, "Bill VanAlstyne W5WVO"
<w5wvo at cybermesa.net> wrote:

> Maybe the original Heath zener wasn't such a bad idea after all. 

REPLY:

A couple of options:

1. Install a 50 watt stud-mount type zener. Part numbers 1N3305-1N3350
and 1N4549-1N4556. Browse the Mouser catalog for the needed voltage.
About $10 each. 

or perhaps even better although more work

2. Replace the diodes with 6A10 type. They have a 400 amp surge
rating. Assuming your B+ lead has a glitch resistor which holds the
dead-short current below that point, they should last forever. For
example, with 3000 volts and a ten ohm resistor, the max possible
surge is 300 amps. The leads are a larger diameter and you'd have to
drill out the PCB or mount them separately. About 40 cents each. 

Good luck. 

73, Bill W6WRT