Transducer choice and selection

[Second Nature]

Looking into getting a furuno fcv587 fish finder for the boat and have heard many good things about them. How ever there are so many transducers that can be used on these units that I'm having a hard time deciding which one to get. I have it narrowed down to transom mount only because when I upgrade boats in a year or two I would like to take the unit with me. So I have two questions. First is, do most people use 600watt or 1kilowatt power transducer for trolling on the big pond? I've heard the more power the transducer has, the cleaner the image you get at greater depths, but is 1kilowatt overkill for what we do? (1kilowatt airmar transducers range from $800-$1300! Ouch). The second question is what angle do people prefer the transducer to have? Some transducers have dual beam options from a wide 45degree beam to a narrow 12degree beam. The wider is better for finding fish but the narrow is more accurate and better for detail at greater depths. So if you had to chose what angle beam would you prefer to use for deep water trolling? Some of the airmar transducers like the tm270w has a 45degree beam and so for every 100' of depth you would have about a 40' circle on the bottom. To much? To little? The choices I've thought about for transducers is the tm258, tm260, and the tm270w. Any input on these units or transducer info would be great, just a tuff decision and an expensive mistake if not made correctly.

[rolmops]

600 watt is fine for the deepest parts of the lake. The 1 kilowatt transducers are good for up to 2000 feet or so,they are great for deep sea fishing. As for width of circle . I happily use the 20 and 60 degree double beam (50/200 kHz) which covers the shallow and the deep nicely. I use an airmar p66 which is a good transom transducer that does not break the bank at all. It is less than a hundred dollars and it gives a good screen at 17 mph which is a nice search mode speed.

 

Airmar suggests the 50 to 200 kHz for sports fishing

Edited May 25, 2013 by rolmops

[cheeseyrider]

Rain or shine I sent you a PM

[John E Powell]

The TM270W is a great transducer. But it does not have a 45 degree angle - it is 25 degrees on both 50 and 200 kHz, These transducers are massive compared to mid-end transducers, about 9-10" long mounted on the bracket. I'm running one through a Garmin GSD24 on my marine network displaying it on a 12" display.

 

If I recall correctly, the TM258 is a 4 element transducer that provides an oval-shaped area of coverage. At 100ft, this would equate to about 25' side to side x 40' fore to aft coverage with a Q of 9 on 50 kHz (that's pretty good), but the 200 kHz side has just 5' side to side x 9' for to aft coverage with a Q of 15 (that's not very useful at all to trollers). You won't see much of anything on the 200 kHz side unless it is directly under your boat. While Airmar classifies this as a high-performance transducer, it is not a high definition transducer and won't provide as good an image as the 260 and 270. I haven't checked the price lately, but I think it is priced a bit less than the other two also.

 

The TM260 is a high definition transducer which has a 7 element 50 kHz side and single element 200 kHz side both having a Q of 8. The 50 kHz side is 19 degrees providing 34' coverage at 100' and the 200 kHz side is 6 degrees providing 11' coverage at the same 100'. The area covered by the TM260's 50 kHz is similar to that of the TM258 (and a similar Q), but the 200 kHz side of the TM260 has about twice the coverage and a much better Q than the TM258. Given the HD capability and the superior 200 kHz side, the TM260 makes more sense for downrigger trolling than the TM258. If I recall correctly, this is the mid-priced unit among the three.

 

The TM270W is a high definition transducer which has a 7 element 50kHz side with a superior Q rating of just 4. The 50 kHz side is 25 degrees providing 45' of coverage which is about 1.6 times more coverage than the TM260's 50 kHz side. The 200 kHz side is a single element with 25 degree coverage with a Q of 15 which is not as good a Q rating as the Tm260's 50 kHz side, but the coverage area of the TM270 50 kHz side is 16 times larger than the TM260's 200 kHz side. Comparatively speaking, these are impressive differences that downrigger trollers can actually put to good use. I'm not sure there is a better transom mount transducer made for our style of fishing.

 

If you did a lot of vertical fishing, then the TM260 might make more sense with it's narrower lower Q 200 kHz side, but if you're going to spend this kind of money over the mid-range transducers, I'd recommend spending just a little more on the TM270W vs. the TM260.

Edited May 26, 2013 by John E Powell