If the transmission frequency of a signal sent by both surface wave and skywave is doubled what will happen to the dead space?
Search me! I've been messing about with radio propagation for 45 years and I've never come across the term 'dead space'. Neither has Wikipedia - at least in the sense of radio signals.
There is something called the
Skip Zone which is possibly what the above question is alluding to. If this is correct, any attempt at a reasonable answer will need to explore a wide range of possibilities since it will depend on the reference frequency chosen for the exercise.
Frankly the question as it stands seems both strange and irrelevant. Has something been lost in the translation somewhere?
FoR