SanDiego, People's Republic of California FEMA District 9
Posts
28,243
An SB-220 was meant to run at 2KW DC input that would be 3KV @ .667A OR THEREABOUTS..... As I remember the approximation formula for plate impedance is the plate voltage over 1.57 times the plate current in amps for a Class B amplifier. My calculator is on the other computer I can not ether confirm or provide any different figure.
73, Sue
AF6LJ Conspiracy Theorists Are People
Who Question The Statements Made By Known Liars.
I thought I could get rich in the stock market by investing in
Viagra, Geritol, And Ginseng but my stocks didn't rise to the occasion.
Hell, I figured that there was always somebody somewhere either trying to
Get it up
Get it going
or
Trying to remember what to do with it.
73 De Bubba
4 out of 5 Seniors prefer the taste of
ALPO over other leading National Brands
Time doesn't heal all wounds. It just makes them more bearable.
No biggie, but AG6K's website showed 23 turns on a Amidon 225A-2 core for 9uH. Using that data
put me below 160 meters and I didn't sweep that low with the CIA analyzer. Online calculators
show 23 turns will be closer to 11uH for that core. I ended going lower than 9uH when the dust settled.
I also did the QSK mod, loosely based on the AG6K website info... unfortunately the exact parts Rich used are no longer
available, but the RJ1a vacuum relay, and a companion Hi-G RF miniature relay, worked FB for the QSK mod. I ended up with
an inductor value closer to 6uh, based on adding about 1800pF padding across the load cap, and another 300 pF across
the plate tune C. Works like a charm. I have to give Rich credit for the motivation to do these mods. They really improved the
venerable SB-220 to a new level.
SB-220 plate impedance?
Originally Posted by WB2WIK
That's Cute Steve.
