View Full Version : single or dual frequncy fish finders

04-09-2005, 08:51 PM
;D I have pretty much narrowed it down to a lowrance color unit but I was wondering who is using the dual over the single and why? Any help would be appreciated ;D

04-10-2005, 04:07 AM
I'm still learning how to use my fish finders. Typically I have used the wider (lower frequency) primarily to try to determine fish depth. The lower frequency gives me a wider cone angle and therefore greater coverage.

The higher frequency I'm finding gives better detail and separation of fish.

Hope that helps

04-10-2005, 08:19 AM
I have a dual frequency on my Raymarine C80. I really can't tell the difference. I'm still learning to use it so that may be the difference.

04-10-2005, 08:22 AM
Dual Frequency finders are great for downrigging. You can pick up both rigger balls.

04-12-2005, 02:47 PM
Unless you have a specific need for a dual frequency I wouldn't get it. A specific need would be Salmon fishing, but only the first part of the year. But all you will be able to see is bait fish. Salmon will not show up in a 50 mghrtz frequency.

Fish sonar works on air. Fish bodies are the same density as water so the signal is bounced off the air bladder in rockfish. Salmon don't have air bladders, but do gulp air to adjust. They also use less air so are hard to find except at the shallowest of depths by good fish finders.

A better investment would be an 800 dollar transducer that sends out like 16 signals. WIth that you can see the bottom, bait, structure and fish at 50 mph. But then you need an 800 dollar fishfinder to put it on. I'm not in that bracket so I just look for bait and structure.

Getting back to the dual frequency. YOu have something like a 50 mghrtz frequency for over 200 feet. This is for deeper deeper water and gives a stonger signal but less detailed

The 200 mghrtz signal means more waves closer together. This translates to better definition on your screen because the closer the wave length the more signal you have bouncing back with more details.

04-12-2005, 06:49 PM
I have the Lowrance X15 with the dual frequency. The dual frequency is good if you're in salt water or charting very deep water. The X15 has a max depth of 3,000' although I don't know why you would want to chart that deep. I fish Tahoe usually in 600' and less so it isn't that big of a deal. It was one of those nice things to have but not a necessity and not much money. Hope that helps. Tight lines

10-23-2005, 03:33 PM
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