Scott Dorsey wrote:
Paul P wrote:
Does anyone have a guess what value choke L112 found here
http://www.ppinyot.com/hammarlund.ht...Supply%20Choke
might be? I am getting a 190 ac volt drop across this puppy. It has a cold
DC resistance of 97 ohms. How I got there is also explained at the
hyperlink page above.

The short of it is, the negative bias voltages are down across all
associated tubes that share that supply. Google is no help.

Even a guess at this point would be nice. I have never calculated a choke
in this configuration before.

The choke has AC going through it, since it's on the input side of the
rectifier. My guess is that it's not just a normal choke but is a swinging
choke with a controlled saturation characteristic. It's acting as a
current regulator; as current rises the magnetic flux in the core rises
and at some point the core saturates and the impedance of the winding shoots
way up, reducing the current flow.

But that is exactly backwards from the way chokes work. As the current
rises, and the core approaches saturation, the coil starts to lose the inductance
enhancement provided by the core, and it approaches the inductance of an
equivalent air core choke. That is, the inductance *drops*, and the inductive
reactance *drops* and the AC current shoots way up.

-Chuck