If you check the installation recommendations on the SailMail website, you will see that they recommend installing a device called a Line Isolator on the coax cable and two ferrite beads on the control cable. This is already on your radio if it was purchased from us. If it wasn't purchased from us, it is a 99.99999% chance that they are not installed. You need these to make your system work properly. They greatly reduce the amount of energy that the tuner cables carry from the tuner back up to the radio when transmitting. It is this energy that can drive your computer crazy and make it do strange things. The kit contains everything you need - and no cutting of cables or soldering is required. Please specify make and model.