[Amps] tube C + stray C

[Steve Thompson]

Scott Townley wrote:
> Measured with a simple B&K capacitance meter (1kHz):
> 3-500Z grid to plate	5.0pF
> 3-500Z inserted into Johnson ceramic socket, recessed about 3/4" below 
> aluminum chassis deck:  10pF
> Seem right?  Kinda surprised that an extra 5pF just from sticking it in the 
> socket...socket grid pins (all 3) are directly grounded to chassis.
I've done the same with various tubes - glass, big and small ceramic and 
I always see the same as you, actual total C is about twice what's in 
the tube itself.

Steve