It is difficult to turn a mod off, it can be done but it would need fet or relay switching, both methods would create signal loss or noise generated by the relay contacts, switches would also cause noise in the sensitive input part of the circuit. One of the biggest problems that we have with detectors is the coil connectors, the tiny resistance of the contacts actually introduce noise into the circuit. To mod a 5000 takes 1 week. I am still working on some big improvements. One word of advice to anyone with old detectors, do not sell them as they will be worth a fortune later this year.. more on that later.