External ATU

Just a random thought. 
Often I see people using relatively tunable antennas with their radios and, from no reason (at least, not a technical justified one), they put external tuners after radios that already have internal ATU's. 
Worst, that tuners have (most of them) coaxial output. 
By doing that, they spend the money somehow useless, bypassing the protections that engineers put on the radios. 
At least, if you put an external tuner, get one that can feed the antenna and not the coaxial cable + antenna. You will be pleased with the results! For the coax+antenna, use the internal tuner and if that tuner can't handle the mismatch, try to fix the antenna instead.

That was removed from FB IC-7300 group as being ”offensive”.