BFO values
1)With one exception, all the published BFO values are positive numbers. Has there been any verified explanation of the "-2" BFO?
2) From an engineering prespective, I would have always expressed an offset as a positive value, regardless of the actual computation (leading to a positive or negative result). However in this case if the required frequency shift was positive, that implies one possibility; if the shift were negative that has contrary implications.
So, has it been verified that all the shifts are positive? Or has this been also left to speculation?