The operator's description separates the two cases precisely, and that is what
identifies the fault. RX alone on SUB displayed VFO B correctly; RX AND TX on
SUB — entirely on the sub receiver — displayed VFO A.
VS was being read as "which VFO is in use". On an FTDX101 it does not answer that
question: with both RX and TX on sub it still reported the main VFO. FR is the
command that selects the RECEIVE VFO, and it is now asked first, VS remaining the
fallback for models that lack it.
Split falls out of the same correction: split means the TRANSMIT VFO differs from
the RECEIVE one, so a wrong receive VFO made the comparison wrong too — which is
the second half of what was reported. A test covers all four RX/TX combinations,
including the one that is NOT split (both on sub) and reads as split if you take
the transmit VFO alone.
rouggy
ccceab9d02