Keeping the oscillator running and keying subsequent stages will usually
produce a more stable signal. However, it is not unusual for some of the
oscillator's signal to leak
The VFOs in all my old Txs stay on all the time. I use a simple RIT
circuit to move the VFO off freq on receive and key it with either
plus or minus depending on the way the rest of the Tx is keyed.
Works neet...
73 W7ZFB