The E120 installed in a 2009 boat never had radar, only DSM300 sonar and GPS (presumably RS125). Am I correct that a RD418D or RD418HD digital radome can be installed with the addition of a Seatalk HS switch which the DSM 300 will also be attached to? If so what is the part number of the Seatalk switch. If not what is the recommendation. Thank you.
Rich
Rich