I have Graupner and Futaba 2.4Ghz stuff now, but use some of my Vintage AM Futaba stuff still.
For 2.4Ghz stuff there are many technologies; you must get receivers to match your Tx technology format. In 2.4Ghz, all the stuff I know of is square-wave PWM, not AM or FM
I use a mix of NiCd, NiHydride and LiPo batteries to power receivers/servos.
I use 6v regulators with 2cell 7.4v LiPos where those are used.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !