I run LMR-400 to my antenna straight out my radio. When I check SWR I use a 3' RG-213 jumper. If I hook up my big amp I have a 12' RG-213 jumper. I keep the amp in the garage. Its a bit of a hassle but I have a wall tube to pull my coax out to garage and then hooks to keep it stretched out. Takes about 5 mins. I leave the 12 foot jumper in place. I also have a wall plate with a shorted SO connector leading directly outside to my ground system. When the storms come I hook that up in case of strikes.
73's