Re: 2 transducers?
I have 2ea. 200 kHz units on my 17' boat. One near the transom, the other on the trolling motor. I think the beamwidth is 20 degrees. I cannot honestly tell you that I get interference between the two. The deeper the water, surely the higher the opportunity for a return from one to be picked up by the other.
With a 20 degree beam, which should be fairly common, your beams could overlap and you could have no more of a resolution problem than you would have with one 20 degree beam because anything that you pick up in that beam, at a given depth would provide you with a return on your display. Question is, where in the beam is the target? The system measures the time out and time back and displays that from a zero reference. Time is depth primarily, so anything at a certain depth within the signal cone of the system shows up.
Didn't do the math, but a 20 degree beam at say 30' would cover an area of say 100' diameter. Anything within that area would show up on the screen. Put two transducers on there, which means that you now have two receivers now watching that 100' spaced 15-20' apart (so now you have a dual 120' fore-aft cone) and both will be watching the same area for a lot of their coverage and anything hit would show up on both screens. The problem would be that there would be an error in the reading on the screens of both systems caused by the difference in timing of both units.
Again didn't do the math, but could, and will if need be; this could result in a slight double imaging of a return; you would have a fish slightly above an identical fish. Probably not bad enough to worry about. But if you want the numbers, I'll do them for you. Maybe I need to do that to see just how big of a deal it is and see if it is worth your effort to install a switch to select which you want....course you could just turn one off if you are not using it. Mine takes about 30 seconds to be up and running from being off.
Let me know.
Mark
