Chuck I am sitting here on the side but this has happened before.
1. The uBitx as it comes from factory,? (you may have a Bitx40 you are not specific) is supposed to be biased correctly and the bias
instructions are supposed to be for set up a new pair of Mosfets. HOWEVER it would only take someone at the factory to be asleep and you could be where you are.
2. There have been a? vast number of IRF510 mafrs over years and they are not all born equal.? If you bought second tier components you may still have issues.
3. (the most useful one - possible GET OUT OF Jail ) . There are or used to be (Ashar Farhan does not ring me up to tell me every PCB rev) a number of top to bottom vias on the PCB around the IRFs.? If you look front to back and against the schema you will pick em up. Some are carring a lot of RF.? These have a rather sensitive plated through hole.? Clearly it is hard to test them with a DVM unless you have a known good PCB along side - ie a reading non Zero on ohms may still be acceptable.? However if fully toasted then putting through a bit of say Cat5e wire or a component lead and soldering both sides may just may get you out of jail. BUT at 30 Mhz the impedance of the fix will not be the same as a thin Cu PCB layer so you still may have a Princess board.?
Enough.
