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
Front/Rear Panel | TS-590SG | Amateur Radio | Communications | KENWOOD USA
HF / All-Mode • TS-590SG Technische specificaties • KENWOOD Nederland
Second Hand Kenwood TS-590SG HF Transceiver - Radioworld UK 01922 414796