[stackj]

I tried using an Aircraft Communication VHF antenna for the Marine radio. The radios operate in different frequency ranges.

When I tested SWR (Standing Wave Ratio) using this configuration, the marine radio was sending 25 watts (High Power) with over 23 watts reflected. This can be tough on your transmitter final RF Amplifier.

I tried cutting off a proportional section of the antenna (The marine frequency is higher, requiring a shorter antenna). This didn't work as the antenna has a network in the base further tuning it to the expected frequency range.

I bought the Comant aircraft antenna for the marine frequency range and 25 watts out had a refelction of less that 1/2 watt.

You will probably want to make this decision in advance as the aircraft frequency antenna may have a different footprint than the marine frequency antenna.

My aircraft freq antenna had a 4 hole foorprint and the marine one has a 3 hole foorprint.