The critical component here is your 2 position coaxial switch. Who makes it and if unknown, has it been measured for isolation between ports? How much power are you running into it?
The port isolation for this popular switch:
Is rated at more than 50 dB between ports.
If this is typical of your arrangement you can expect to hear yourself *extremely* loud and clear in your other receiver which will probably require you to pay attention to its RF gain control in order to avoid swamping the front end.
Your mileage may vary. Proceed with caution.
73 de na6m
If you use DDUtil, you can slave one rig to the other so it follows you around the bands. It has been helpful to record my 6500 on the 1500 to test different audio configurations. If I want to hear a weaker signal, I just reduce power.
I also have both rigs connected to my Bose companion 2 speakers and they sound very similar to one another.
1500 watts reduced by 50 dB yields 15 mW. About 1 year ago Graham KE9H posted an Official Response that the maximum power that a 6500 or 6700 receive input could accept was "about +8dBm." +8dBm is approximately 0.0063096 watts. This seemed illogical because +8dBm is approximately S9. Therefore I am using front end protectors on all RCVR receive only inputs. Some are DX Engineering DXE-RG-5000's and the others are Array Solutions AS-RXFEP's. All RCVR inputs are connected to receive antennas and so far none of the front ends have been damaged so I don't have a basis to recommend the DX Engineering vs Array Solutions front end protectors (receiver guards.) They both appear to work.