The latest radios with SWR protection/monitoring usually set at 2.0 SWR will shut off when they are keyed. Friend of mine had a Fatboy 1x6 with staged driver that was shutting a Lincoln 2+ V3 off as soon as it was keyed. He said the amp worked fine with a Galaxy Saturn.
Anyway, I called my tech friend, and he made a custom jumper that goes between radio and amp input. All the tech had was LMR 400 at the time, so I had him make it, and it ended up being around 15 feet long. Can't remember the exact measurement. He was using a formula with velocity factor and whatever else. Anyway, jumper worked great, and the radio SWR monitoring was showing round about what I measured with an antenna analyzer. No more radio killing power to finals.