[Collins] help re tuning choke in ps

[Dr. Gerald N. Johnson, electrical engineer]

With 27 mfd and 10 Hy, the filtering is good enough, don't need to tune
the choke. But it wouldn't hurt to put a high voltage MOV across the
choke to absorb the occasional inductive kick when the load stops.

The other problem with tuning the choke is that the typical 10 Hy choke
is a swinging choke, or at least changes inductance some with current.
That's a standard feature of iron core chokes. A swinging choke (has not
much air gap between with E and I laminations) can change inductance a
factor of ten or more. A fixed choked not designed for tuning can change
inductance 2:1.

Its important to have enough bleed current to keep the output voltage
from soaring at no load. There are curves in most recent editions of the
ARRL handbook that can be used to select that bleeder resistor.

73, Jerry, K0CQ, Technical Advisor to the CRA
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.