I have a Simrad RD68 with an Intermittent receive problem? I can always transmit OK - verified by another boat - but I can't always receive? - Is this a problem with the set? - I am ready to purchase a new radio as I have cleaned all the connections without luck. Also - would you recommend purchase of the same set - I figured I would be able to install it myself (not too sure about the MMSI though)????