Assuming identical setups and a perfectly vertical antenna, what
percentage increase in range would be likely as a result of changing
from a 3db to 6db VHF antenna?


I have both and to tell you the truth the only difference I see is that a boat
on the fringes (noisy signal, low S/N ratio) on the 3 dB gets a bit clearer on
the 6 dB. I assume it does the same general thing for my transmittedf signal.
It isnt as big a deal as you might think, no dramatic range increases. I think,
from my experience,that antenna height is the more dominant factor, not antenna
gain.