Hi folks,
I'm new to the forum and new to saturated fet amplifiers. I've never done any switching ps design. After emailing Steve for some advice and PWM kit availability, I've decided to build an 8 fet 400 watt rig for 80 & 160 - very close to Steve's published design - and am checking out availabilities of key parts. All seemed well until I tried to source these exotic ATC type caps. I've done limited surface mount work, and the RF caps I'm use to are either the fist-size mica caps - or the "unelco" style.
I'm gathering that the voltage rating should be similar to the fet - about a Kv? And really low esr is important?
What are folks using these days? The closest I could find were some that were almost $40 each.
Also, I see that Steve bandswitches the drain-to-ground caps with relays? Series inductance isn't an issue?
Could I use fewer drain-to-ground caps, and then resonate the push-pull output with a floating 1000 pf vac var between opposing drains?
If anyone has the exotic caps for sale I'm interested.
Chris