[Amps] How best to reduce filament voltage?

[Jim Tonne]

Vic:

Right on!  I was ignorant of that little bit of information.

In which case:
>>> This will not work. Don't do it.

- JimT



----- Original Message ----- 
From: "Vic K2VCO" <vic at rakefet.com>
To: "Jim Tonne" <tonne at comcast.net>
Cc: "Tom W8JI" <w8ji at w8ji.com>; <w2cqm at juno.com>; <amps at contesting.com>; 
"Norman Hockler" <sanorm at columbus.rr.com>
Sent: Friday, February 02, 2007 11:04 AM
Subject: Re: [Amps] How best to reduce filament voltage?


> Jim Tonne wrote:
>> Tom wrote:
>>
>>> This will not work. Don't do it.
>>
>> in reply to
>>
>>>> Install a resistor on the primary side of the transformer.
>>
>> which is what I would have suggested.
>>
>>> It will totally hose the voltage regulation under load,
>>
>> The load is constant so "regulation" in the usual sense
>> (same output voltage with varying load value) is not an
>> issue.  A series resistance would limit inrush.  A series
>> resistance at the transformer primary would limit inrush
>> to the transformer as well.
>
> Tom is assuming that everyone knows that the transformer in the SB1000 is 
> used for BOTH plate and filament supply.  The resistor would screw up the 
> regulation of the plate voltage.
>
> -- 
> 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco
>