Are the serial/power cables for all units mechanically identical?
Almost. The head on the cables for the SporTrak and Meridian families are identical. The housing of the 330 (and 315 and predecessors not covered by this FAQ) has a flat back while the newer models have a curve to them. The pinouts are the same and it’s possible, if you’re patient enough, to use the cable from one family on the other if you bend the “fingers” on the cable out to increase their reach a little.