This radio gets a lot of bad rap for being a junker and it's justified. the driver is weak and not attached to the heat sink because the pinout is backwards..... And it gets wicked hot but if you want more juice out of that, remove r81 and put a 100 ohm resistor in place of r79 to put it in class c bias. (The tuning coils on both the driver and output need to be changed out with a tower coil with a slug)
For the irf-520 Mos I would use en 2030 or the appropriate resistors/diode as I did. I was only able to achieve 18 Watts out of it with the stock driver in class c getting really hot. Remove r83 and c86 as well as c87.
So back to that driver, I got a wild hair and decided to put the old final in its place since it's just reverse pinout and I would be able to bolt it to the chassis. Ehh probably could have worked better. Then I pulled that out and put in an irf510. Once I figured out my bias voltage this actually sounded pretty good but again I wasn't getting the peak readings I wanted to see. So for irf510 driver I used the same (homemade) bias part as the final but I also ran from the 8-volt TX line a 15k resistor to give the driver enough bias to wake up. It actually sounded real good.
Vr3 is the AMC pot.
As far as the output tank parameters I was not able to maximize that before I threw smoke in multiple spots and made the audio transformer hot
For the irf-520 Mos I would use en 2030 or the appropriate resistors/diode as I did. I was only able to achieve 18 Watts out of it with the stock driver in class c getting really hot. Remove r83 and c86 as well as c87.
So back to that driver, I got a wild hair and decided to put the old final in its place since it's just reverse pinout and I would be able to bolt it to the chassis. Ehh probably could have worked better. Then I pulled that out and put in an irf510. Once I figured out my bias voltage this actually sounded pretty good but again I wasn't getting the peak readings I wanted to see. So for irf510 driver I used the same (homemade) bias part as the final but I also ran from the 8-volt TX line a 15k resistor to give the driver enough bias to wake up. It actually sounded real good.
Vr3 is the AMC pot.
As far as the output tank parameters I was not able to maximize that before I threw smoke in multiple spots and made the audio transformer hot