The first filter choke for the old Hammarlund SP400 (pp 6F6 output in an 18
tube set) is shown as 150 ma. @ 150 ohms with 12 henries if that eases your
possible anxiety. VE7AFN.


"Jack" wrote in message
...
Thanks, gb and Colin for the tips. My guess at about 200 mA is ok, I guess.
The choke is pretty charred... all the varnish was boiled out and dried on
the chassis. The outside paper is brittle now. The filter caps seem ok. I
checked them last night and they have between 35 and 50 microamps leakage at
full charge and working voltage. Today I will wire the choke back in and
use a Variac to check for abnormal current draw. I'm not discounting a
shorted turn or two inside the choke although the dc resistance seems
normal. I did just buy a 10H, 300mA choke on Ebay with about the same form
factor.

The power supply filter is the classic pi with 40uf input and 80uf (!)
output. That capacitance combined with 7 Hy sure doesn't seem anywhere near
120Hz for filtering. But what do I know? Thanks again.

Jack

"Jack" wrote in message
...
I'm looking for the inductance and current rating of the HQ-180A power
supply choke so I can find a suitable replacement. Mine burnt to a crisp
although it still shows continuity. It reads about 250 ohms and on the
DMM's Lx function it says 7.0 Hy. Thanks for any help.