cross-talk between phono and FM in Luxman Tuner-preamp TP-117

Acquired this Lux Tuner-preamp and it is exactly perfect except for one little detail:  I switched to phono with no intentional input signal, turned up the volume, and heard ... FM ... it's not really noticeably audible when I play a record, but I wondered what would cause crosstalk between FM and phono and whether there's somethin' to do about it ... 

Thanks