do I have to switch back and forth to listen to both.
You can switch back and forth between frequencies, to listen to both
(not simultaneously) without having two VFOs. You just need one VFO with
two (easy to switch between) memories. This is what most transceivers
with an A and B internal VFO have. They typically do not really have two
VFOs.
If you truly have two VFOs, as was common with separate matching
transmitters and receivers (such as the Drake 4 line, Heath SB series
and Collins S-line) and some older transceivers with external accessory
VFOs, then it is possible to have both VFOs combined into the LO port of
the mixer and receive two frequencies (on the same band) simultaneously.
I have never operated a rig that had this feature from the factory.
Apparently there are several rigs that have this feature without
modification, and some of them have a control that allows variable
relative levels of the two VFOs and therefore of the two received
frequencies.
DE N6KB
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