Steve,
I still have my Rev 1 QDX running.? It is built for 12 volts, but I run it between 8 to 10 volts.? That, to me, supports Hans's statement.? The one mod that I suggest is adding a 1n4148 diode across L14 to prevent the end-of-transmission spike observed on the QDX.??
The AMS1117 regulators have a low dropout voltage, so you can run it at a lower voltage than the 7805 replacement.? It should be good down to just above 6.2 volts.? That gives you a lower power option than the replacement with a dropout at 7 volts.
73
Evan
AC9TU
