I know this is an old thread, but just for anyone bumping into this, I can confirm that the BR24/3G/4G radars branded Simrad, Lowrance, B&G are exactly the same. I know as I recently received a replacement that said "Unbranded" on the box but it had Lowrance stickers applied (as they know I've got a Lowrance).
The only difference is whether you have:
- No interface box
- A RI-10 interface box
- A RI-11 interface box
No interface box is apparently against EU rules for radio interference
, but as a private person do you really care?
The _real_ function that the interface box has is that it injects heading data into the radome, so that the radome can tell the chart plotter on which heading a particular scan line should be showed. This is nifty, as it removes any timing issues between when the scan line was "taken" and when it is received by the chart plotter. This heading input is needed for the chart plotter to perform MARPA. I'm not 100% sure, but I think that nowadays even all Lowrance 3G/4G boxes include the RI-10 or RI-11.
An RI-11 uses a high speed NMEA-0183 input (any brand, as long as it has 10 Hz update) and an RI-10 uses Simnet/NMEA-2000 heading input (any brand, all brands supply high-speed updates on NMEA-2000).