ISP does not use 42.420Mhz anymore.They are keeping 155.370 Point to Point and 155.475 for ILEEN.for Dispatchers to listen to statewide. Most of the Low band has been taken out of the ISP cars statewide and has been replaced with safe-t.Most of the old low band equipment has been stockpiled at Indianapolis where the cars are put together before they go out on the road.You might want to watch the local hamfest.These will make excellent 6-meter ham radios.