The only thing I can tell you here is, "The AT 230 WILL NOT handle 500 watts."
Good luck on your tuner hunt.
Barry
Yep!
Besides that very important issue:
I had an AT-230. It was pretty, nicely matched
the appearance my other Kenwood gear, but
otherwise I thought it was a poor to mediocre tuner.
GL ES 73, Ken AD6KA