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Hoffman Amps Forum image Author Topic: Triode pentode switch  (Read 3463 times)

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Offline 67polara

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Triode pentode switch
« on: February 07, 2011, 05:57:34 pm »
I can not find a switch with a high enough rating (voltage) to do the triode pentode switch.  Will one with a 250 volt rating work?  Should it be a Plastic bat type or will a metal bat type work safely?

Tony

Offline Willabe

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Re: Triode pentode switch
« Reply #1 on: February 07, 2011, 06:14:49 pm »
The old Fender power and standby switches were'nt raited for the full voltage either, they raised the current raiting to make up for it.
The standard carling power switch they used is raited at 3A @ 250 V. They held up well for many, many years. Fenders were metal bat type, but I guess plastic would add to your safty.

Doug has them in his store, metal bat anyway.


         Brad        :smiley:   

Offline PRR

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Re: Triode pentode switch
« Reply #2 on: February 07, 2011, 08:22:11 pm »
The voltage _change_ is about zero, maybe 5V-10V drop in OT winding. That's what the contact specs cover.

The voltage from terminals to chassis (or you!) is a steady high voltage. Don't use a mini-tiny switch. Anything like the usual Standby switch (except DT) will be fine.

Offline 67polara

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Re: Triode pentode switch
« Reply #3 on: February 08, 2011, 12:21:39 am »
Thank you.  Just didn't want to fry myself.  I think I will use a metal bat type switch but I think I will dip the bat in liquid tape or get a cover for it just in case the switch might fail.

Tony

Offline jeff

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Re: Triode pentode switch
« Reply #4 on: February 11, 2011, 09:41:38 am »
 The screen voltage is close to the plate voltage. But what about at full swing in pentode mode?

 


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