Sonar Questions

[Island Runner]

A few questions here regarding sonar. I run a Northstar M84 plotter with 1000 watt B260 50khz/200khz transducer.

#1. Transducer Peaking. When "peaking" your transducer, say at 30ft, when do you guys feel the need to "peak" it again? I have been reading a +/- 20% change in depth will require the transducer to be "repeaked". That is only a 6ft change and it seems to me, being we fish in relatively shallow waters, I would need to "peak" the transducer many many times during the course of the day. How often is this really necessary?

#2 Sonar frequency and cone angles. I am having trouble deciding which frequency to run on my sonar. I am told that 200khz is better for the shallow water we fish and is more detailed but my cone angle is only 11 degrees. On the other hand 50khz has a much wider cone angle at 45 degrees but is less detailed and suited more for deep water. My problem is this: If running the 200khz at 11 degree cone angle in 30ft of water, I am only covering 7-8ft of the bottom. If the if the fish are suspended half way up the water column, I would only have a 3.5-4ft coverage area at that 15ft depth. It seems to me that there could be many fish there and I would not see any of them. That bothers me! On the other hand, using the less detailed 50khz frequency in the same 30ft scenario, I would be covering 25-30ft of the bottom. Now the geometry of it.

200khz 11 degree cone in 30ft of water = 8ft diameter circle= about 50 square feet of bottom coverage

50khz 45 degree cone in 30ft of water = 30ft diameter circle = about 700 square feet of bottom coverage

That is nearly 14 times the area of bottom coverage! Am I thinking wrong here for wanting to run 50khz just for the greater coverage yet less detail? What are your opinions?

#3 Sonar Scroll Speed. What do you guys feel is the best speed to scroll your sonar speed? Slow, medium, fast? And why?

[Fish Tales]

I would suggest contacting this gentlemen Gil Travis he’s on the west coast. His number is 800-925-0341 Gil by far knows more about transducer than anybody I have ever talked to. Reel Time turned us on to him.

Kevin

[Gettin Jiggy]

I would suggest contacting this gentlemen Gil Travis he’s on the west coast. His number is 800-925-0341 Gil by far knows more about transducer than anybody I have ever talked to. Reel Time turned us on to him.

Kevin

I agree, call Gil. We just bought a tm260. And Gil hooked me up! He will have answers and solutions. Super nice guy will answer the phone day or night.

[ReelTime]

Like they said call Gil. His knowledge of sonar and transducers will blow your mind. Super nice guy and loves to help people.

Your B260 does not run a 45 degree cone angle. The 260 transducers have 19 degree at 50khz and 6 degree at 200khz. For shallow water of lake Erie all you need run is the 50khz. Here is a link to the specs.

http://www.airmartechnology.com/uplo...hures/B260.pdf

I run a Furuno sonar with an Airmar P66 transducer. It's not as powerful as the 260 but it gives me a 45 degree cone angle at 50khz which works well in shallow water. Keep in mind shallow water when you are talking sonar is under 100 feet. You have to remember that the saltwater boys fish in 100's of feet of water all the time. In 30 feet of water I'm viewing at a 25 foot path where in 30 feet of water you are only viewing 10 feet. The big trade off is the P66 does not mark fish as well at planing speeds as the 260. I have been thinking about installing an M260 (shoot thru ducer) for when I am running at planing speeds and then switching over to the P66 once I start trolling. Best of both worlds that way. Here's the P66 specs.

http://www.airmartechnology.com/uplo...chures/P66.pdf

Like we have said...give Gil a call and he can straighten you out.

[Island Runner]

Thanks for the info and phone number. Reel Time, you are correct in the cone angles for the B260 transducer. I got the 11 and 45 degree cone angles from the owners manual to my M84 plotter never giving a second thought to question of how the owners manual knew what transducer I was running! Thanks for straightening me out. I will be giving Gil a call this afternoon. Thanks Again.

[Fish Tales]

Reel Time I have added a shot thru M260 to my center console I'll let you know how it works while making white water. Thanks for turning me onto Gil although he's ponited out that my Lowrace is not what I thought it was.

Kevin

[ReelTime]

Reel Time I have added a shot thru M260 to my center console I'll let you know how it works while making white water. Thanks for turning me onto Gil although he's ponited out that my Lowrace is not what I thought it was.

Kevin

Sounds great. How easy was the M260 to install? It looks pretty simple as long as you have good access to the bilge which I have. Which Lowrance are you running?

Talking to Gil was one of the reasons I switched to Furuno for sonar. It's a different animal but once I got familiar with it I liked it. I have been using a Lowrance LCX-28C just as a chartplotter along side of the Furuno sonar. Found a good deal on a HDS-7 chartplotter so I'm installing it now and sold the LCX unit. I like running the two seperate units as aposed to one combo unit. Just seems to give me more options.

Island Runner let us know what Gil has to say. I'm interested in hearing.

Wes

[Fish Tales]

Wes,

It was the easiest install I have ever done. I spoke to Pro-Line to confirm that the hull was not cored in the installation area. Luckily the hull is flat so I got a large tube of 3M 5200 and glued it down. Then I resealed the edges with 5200 inside and out I’m just waiting for it to cure so I can finish the install. Our marina doesn’t open the gate until April 1st so I should be ready by them.

Kevin