[Amps] 3-500Z heater voltage reduction

[Alek Petkovic]

Yep, the resistor in the primary is the ideal way to go. I have a 
fixed value 22 Ohm resistor in my 3-500 amp and as Phil says, it 
doubles as a soft start.

Alek,
VK6APK

PS: Mike, I just looked you up on QRZ. Nice puppy.



At 11:55 AM 16/09/2009, Phil Clements wrote:

> > Or some other common junk drawer stuff that would do the trick ... the
> > last thing i tried was a .27Ohm 10W cement resistor and that was too high
> > of a resistance ( was a bit surprised but oh well i dont know the internal
> > resistance if the filaments anyways)
> > KC7NOA ... i think i even have some nichrome sitting round some where.....
> >
>
>Put the resistor in the primary of the filament transformer. This gives you
>a free step-start; the in-rush current will be reduced. Get a 25 ohm 50 watt
>resistor with a slider to adjust the voltage. You want to set 5 volts at
>each tube pin. Not the socket, but the pin where it protrudes out the bottom
>of the socket.
>
>(((73)))
>Phil, K5PC
>
>
>
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