The lock is independent of which VFO you are using for TX and RX. All you have to do to do what you want is put the DX frequency in VFO B, turn the subRX on, put the TX frequency in VFO A, and do NOT turn Split on. Whether you lock the VFO B knob or not is incidental to this setup; you only need to lock the VFO B knob if you are in danger of touching it accidentally.
The Split indicator in a dual RX K3 is misleading. It does not necessarily mean you are operating split; it just means the TX is on VFO B. If you want to operate split with the TX on VFO A, just turn Split off and listen to the DX in your subRX (right ear).
---In Elecraft_K3@..., <g8ajm@...> wrote :
Rich many thanks but that seems to give me the "normal" locked B for TX with the RX tuned on A. I do it a slightly different way but achieve the same thing for use when running.
I'm looking to do the exact opposite i.e. a fixed (locked) RX frequency on B and variable TX frequency on A (the large knob). This so I can listen to the DX on a locked RX frequency and move the TX vfo quickly and precisely with A while viewing the P3 display.
73 Chris G8AJM