TS-590S KENWOOD NETWORK COMMAND SYSTEM Setting Manual
Kenwood TS-590S New Firmware released ‹ SPARKY's Blog
User manual Kenwood TS-590S (English - 92 pages)
Kenwood TS-590S Ремонт (repair) - YouTube
The cheap Chinese copies of the Kenwood TCXO boards are rubbish, I bought and installed a superb TCXO from Mark Goldberg, W7MLG. The results are fantastic, my TS-590SG is now spot on