If you are running big power you need to get a better suited antenna that handles a lot of power like a shockwave with a din male or direct feed connection. JMHO. You may be able to mod it but using SO239 and PL259's has to go. The sirio ratings are over inflated a bit in sure as most antennas manf. Do this, but an antenna like the shockwave or Similar antennas are built for power and long term use of it. It's cost more, but you won't be spending a lot of time and maybe some burnt equipment trying to figure out how to prevent this issue from happening on the vector. The Interceptor 10K or 25K antennas, made by Jay in the Mojave, is another antenna that comes to mind. Again not cheap but handles a lot of power. JMHO. The Shockwave antennas are made in the USA as well. Not the Australian ones. Again this is JMHO. There may be a fix for what your issue is, arcing, but Idk or haven't seen anyone speak on the subject of upgrading it to handle more power than its rated for, which again I think is overinflated. Hope you find and answer and have a great day!!