[Amps] AC or DC better for indirectly heated cathodes?

[R.Measures]

>On Wednesday 19 November 2003 13:09, A.J Moss wrote:
>snip
>>     If I were to make a floating adjustable regulated DC supply, I could
>> use an ordinary pot to control the heater volts, meter it, and have a fine
>> adjustment to within ca. 1V either way to set optimum heater volts. I could
>> also then add a current limiting option on the regulator to limit inrush at
>> switch-on
>>
>>     Are there benefits, advantages, or just risks of using such a scheme?
>> Constant unvarying power at the heaters seems good, but is 'less' 'more' to
>> use the cliche.

>Repays itself in no time at all if you're ever going to operate portable.
>
**  True, but there is no reason to limit inrush-current to heater-type 
tubes.