[Amps] plate choke

[Mark Marsden]

Hi Amp'ers

When I was building my amp I spent a long time investigating plate
chokes or feeding DC in from the antenna end. I made 5 chokes, and
bought one from a UK manufacturer, but could never get enough inductance
for 160m without introducing a series resonance below 40MHz. 

The end of my search came when I bought some RFC-4L 500uH anode RF
chokes from RF Parts. I was very impressed to see no resonances between
1 to 100MHz. 

FYI photos of the choke under test and a VNA plot of it's impedance are
shown 
on http://granta.digital-crocus.com/Linear_design_notes.php3 (scroll
down to the heading "Anode Choke testing")

73 Mark G4AXX