23-05-2013, 05:52 PM
It's a common sort of problem - you really need to kill the signal sources as well as switching them out. It's almost certainly capacitive coupling. It could be in the switch itself.
If the coupling is in the switch itself, one way forward - which would require a more complicated switch - is to break the signal source not by a single contact, but by two in series. Then the mid-point connection (which 'floats' when the two contacts are open) is itself shorted to ground by a third contact which closes when the other two are open.
If the coupling is in the switch itself, one way forward - which would require a more complicated switch - is to break the signal source not by a single contact, but by two in series. Then the mid-point connection (which 'floats' when the two contacts are open) is itself shorted to ground by a third contact which closes when the other two are open.
