[AMPS] filament rheostats

[measures]

>Rich says:
>
>>So when are amplifier manufacturers going to get off of their lazy butts
>>and start building amplifiers. with a filament adj. rheostat and a means
>>of measuring filament potential?
>
>I guess they don't because of number 1, cost,

The current cost of 25w rheostats in the Mouser Catalogue is minimal.
//  I received one e-mail from a chap in a country where electric-mains
potential varies from c. 95 v to 125v.

> and number 2, the capability
>of allowing people to wind up the volts - 'gee, Wilma, you get more
output'.

  No further increase in output occurs when filament potential is
increased above what is  needed to secure full emission.
>
>Better, but even more expensive, is a regulated filament supply that is
>current limited so the inrush current can't exceed twice the normal
current,

The only tubes which seemingly have this limitation are the 3-400Z and
3-500Z.

>and doesn't vary with line volts. You can afford to build that sort of
thing
>into a home brew amp.......but commercially it's a no-no.
>
A simple rheostat would be a cheap fix.

cheers, Peter
>
>


-  Rich..., 805.386.3734, www.vcnet.com/measures.
end


--
FAQ on WWW:               http://www.contesting.com/ampsfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm