[Amps] 3-500Z glitch resistor

Vic K2VCO vic at rakefet.com
Sun Sep 7 10:21:27 EDT 2008


Everyone seems to agree that a glitch resistor between the plate choke 
and the HV supply is a good idea, to limit huge current surges due to 
arcs caused by gas, etc. But recommendations for the value seem to vary 
all over the map.

For a single 3-500Z, I have heard the following:

10 ohms 10 w
15 ohms 10 w (R. Measures supplies this in his kits)
25 ohms 25 w (I've used this in the past)
50 ohms 3 w

My feeling is that no power rating less than 25 watts should be used 
because of voltage considerations. And if 50 ohms is chosen, it will 
dissipate 8 watts during normal operation with 400 ma. plate current, so 
  even assuming a 50% duty cycle, a 3 watt resistor is marginal. And 
certainly the voltage rating is inadequate!

Any suggestions or comments?
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco


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