I have a mast
top and a rail mount Vhf
antennas mounted. I did actual experiments on range and signal strength. Swapping the coax on the back of the radio
to first one antenna
then the other. Found that both provide about the same range and the same signal signal strength on both transmit and receive.
of the top of mast antenna
is challenging. In future, I doubt I will install another antenna on top of my sailing main mast opting instead for just a rail mount on my Bimini
frame. Way easier to inspect, clean, adjust and install.
Why are they the same? I don't know. Perhaps it's the loss in the coax because it's a considerably longer coax run through to the top of the mast perhaps it's some other reason. Don't really care. I encourage everyone to do these tests on their own boat
. Make up your own mind.