so is it fair to say that the higher the voltage you can run it all on the higher the power..? does increasing the antenna length in wavelength multiples etc have apractical power increase..?
A higher voltage gives the circuit access to more power, but if the circuit isn't designed to convert that power into useful RF it just gets hotter.
Increasing the antenna length in wavelength multiples might change things, but you don't know if the signal transfer is improved or degraded. It can also change the radiation pattern, but again unless you know what you're doing it might get worse.