On 04/17/13 00:06, Drax Felton wrote:
So then what is the Radio Handbook talking about where it uses a 10ohm/20w
one between the plate choke and the +HV?
From: Jim Garland [mailto:4cx250b@miamioh.edu]
That's going to be quite a resistor, inasmuch as 4KV across a 30 ohm
resistor amounts to a half million watts of dissipation! A 4KV pulse 50uS
wide, once per second, would dissipate 25W.
So where does one find a 30 to 50 ohm 25 watt resistor that can safely
handle 4000v?
The 4,000 Volt rating is not across it, it is from the resistor to
ground through the mounting hardware. (in this case)
If an arc occurs in the tube (for instance) there will not be 4,000
Volts from the power supply. (for long)
--
Ron KA4INM - Youvan's corollary:
Every action results in unwanted side effects.
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