[TenTec] Herc II vs Astron

[Steve Hunt]

N6KB beat me to it!

My schematics show nowhere the 4 supplies are connected together; but 
you do need a fifth, low current, supply to power the DC distribution 
board in the amplifier. In the 9420 they derive that supply - and the 
one to power a separate transceiver - from the four main 14v rails 
through a couple of full-wave bridge rectifiers. The bridge rectifiers 
ensure they don't inadvertently "parallel" the four main supplies.

I wonder how you are providing that fifth supply?

Steve G3TXQ