Which metal is better to yield RF radiation?
Anything that conducts electricity will block radio waves. However, anything conductive that is not earthed can *emit* radio waves. If the transmitter’s housing is not earthed, then it and the aerial will form a (badly-matched) dipole and both ends will radiate a signal. The signal coming from the box (it’s actually coming from the surface, not through it) will be out of phase with the signal coming from the aerial, and this will create an interference pattern of strong and weak zones. Just connect the transmitter housing to mains earth. Your signals will travel further that way, and your RF output transistors should run cooler because you will get a better SWR.
