Hcca 2100 psu repair

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SS64

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Joined 2008
Ok been out of the hobby for a few years.. I've been living in the land of tubes and RF ever sense I got my ham radio license.. Any who.. I have somebody that has been begging me to fix there amp so I decided to tackle it... The amp came to me with blown outputs, blown drivers and a blown supply. So I started by doing the usual.. Removed all the physically burned parts and replaced them. Removed all of the outputs. Removed all of the supply fets and fet drivers.
So with all the outputs removed I began to rebuild the supply. I replaced all of the 10 ohm gate drive resistors. Replaced the 56 and 06 fet drivers. Replaced the tl494. I used irf3205's instead of the 60n06's in the supply.
When I apply power only one half of the supply is working. Pulled out the scope. Now I know or at least I think if memory serves I'm supposed to have a square wave on the gate of the fets.. Well from what my scope tells me I have a square wave but they seem to be distorted.. In other words it is far from a perfect square wave...
Does anybody have an idea of where I need to dig into next? Bad resistors or caps?
Any help is appreciated...

Thanks

Sam
 
S

SS64

Member
Joined 2008
ok, did i miss some more drivers further upstream? I did replace all of the mpsa56/06's that are immidatly next to the supply fets. All 8 of them. Now i did decide to check my drive signal to the 56's and 06's and i have a much better square wave. there is some roll off on the leading edge and a small spike on the laging edge...
 
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