single or dual transducer

[kalla man]

what is the difference between a single and a dual transducer when it comes to fishfinders??
Im trying to decide if the extra money is worth it.

thanks

 

[Reel Poor]

Re: single or dual transducer

A dual frequency transducer transmits sonar at 50MHZ or 200 MHZ, 50 MHZ being for deep water (300+ feet) and the 200MHZ for shallower water.

Here are some good articles

About Depth Finders

More About Depth Finders

And Last But Not Least

 

[Tacklewasher]

Re: single or dual transducer

(KHZ, not MHZ)

Pretty much the dual are for deeper water.

Was out in a friends boat who has dual freq (Lowrance X-25), but in a deep lake (up to 400 feet). The 200 MHZ showed far less then the 50 mhz did, but I'm thinking it had more to do with the cone angle (6 degrees for the 200 vs. 19 degrees for the 50) than the power. A single freq has a 20 degree with 200 mhz. As I do not hit the ocean at all, I am looking at a single frequency unit (either the Lowrance LMS-334 or the Eagle FishElite 642C).

Lowrance has a good tutorial on the whole unit.

http://www.lowrance.com/tutorials/sonar/sonar_tutorial_01.asp

 

[MikeV4]

Re: single or dual transducer

(KHZ, not MHZ)

Pretty much the dual are for deeper water.

Was out in a friends boat who has dual freq (Lowrance X-25), but in a deep lake (up to 400 feet). The 200 MHZ showed far less then the 50 mhz did, but I'm thinking it had more to do with the cone angle (6 degrees for the 200 vs. 19 degrees for the 50) than the power. A single freq has a 20 degree with 200 mhz. As I do not hit the ocean at all, I am looking at a single frequency unit (either the Lowrance LMS-334 or the Eagle FishElite 642C).

Lowrance has a good tutorial on the whole unit.

http://www.lowrance.com/tutorials/sonar/sonar_tutorial_01.asp

KHz it is..... 8)

Khz is the frequency which the sonar will emit the sounds, not the power, the power will be shown in Watts. 200KHz will mean it will send 200.000 pulses per second and recieve. What you need to do with fishfinders or sonars is to understand what you see on the screen, it might be full of fishes showing, but only the r/h side of the screen is actual timing, all the rest of the screen is the past. It is possible this is all caused by one tiny fish swimming around in the sonar range (ie if you are laying still). The sonar does not determine a exact position of the fish either, it emits in a cone form and anything in the footprint is returned to one point. It will not know if the fish is on the r/h, l/h, fwd or aft of the footprint. So what you see is not a representation of what is actually under the boat. The Dual beam emits in two frequencies (freq depending on manufacturer) and has to sizes of cones, ie 20 or 60 degrees. If you are in an area with mostly shallow waters a narrow beam will do, if you have deeper water a wider beam is advised.