Hi,

I really would not advice using a AC-adapter while "playing" with the pc-simulator.
A French modeller had his Graupner MC12 fried while having his TX connected to the PC and then connected a 12v-battery charger to the TX with a 12V-power supply to the mains. Also the house main-fuse jumped off!
He's now looking for another transmitter...
His PC is still running...
Just know that with the crystal removed from your TX or the RF-module removed, the transmitter is only drawing about 30mAh current instead of about 240mAh, that's about 1/8 of the normal consumption.

Olivier