KENWOOD, TS-590SG, Transceivers Base HF-6M, TS590SG
Kenwood TS590SG Transceiver - 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