Trouble at the higher frequencies.

[SV Odyle]

I have been cruising in the Latin American waters of the Pacific Ocean for the past four months. I have had great success and have been very active in the SSB and HAM nets between 3 and 8 Megs. Now that I will jump off the continent and cross the south Pacific I need to have dependable comm. with the nets between 12 and 21 Meg.
When I try to contact these nets I experience two differant problems, the first problem is poor TX distance and a high power meter reading. I see voltage drop across my battery bank and the power meter goes to the maximum reading when I key the mic, but I am not getting out. Normaly I see maximum power when I speak into the mic. below 12 megs.( maximum TX power with voice modulation).
The second problem is associated with good TX. distances but, the meter remains at the maximum power reading for 10-15 seconds after TX. my receiving party reports good propigation but I cannot hear there response for the time my meter is at maximum. It seemed a tuner problem so I reterminated several circuits and checked my ground plane, all seems ok. I am using the same IC- M600 and IC- AT 120 tuner that has served me for seven years. My voltage is always good and the ground plane was renewed in Nov.
I make the puddle jump in two weeks and have no access to a tech. short of a two and a half week sail to Panama City. I have four semesters of electronics study under my belt and lots of practical experience as well. My wife was an electronics tech. before studieing Physics. Seems we can work this out with out loosing this cruising season? Any Ideas?
S/V Odyle

[Jerry]

try a different antenna / tuner / radio.

Sounds like you have a problem with yours.
since you are there and I am here and this post is almost 2 years old, I take it you found a solution to your problem.