Steve,
thank you for the suggestion. I did check the voltage on the gate of the 144M MOSFET and it did vary as I turned the knob, the the supply current didn't change.
I have now ordered another transistor on the assumption it has blown. Quite probably it has nothing to do with the driver board failure, but more likely at some time I tranmitted into an un-terminated socket. Since I don't use 2m often, it could have gone unnoticed for some time.
regards...
--Gary (M1GRY)
