Is 200khz single frequency good enough for fishfinder?

[canman]

Alright everyone. Is getting a single frequency (200khz) good enough for fishing walleyes? Up to 60 feet of water? What are your recommendations? I want to upgrade and would like some additional advice based upon your experience.

Thanks

[PerchJerker]

I think so. But if you're not sure the dual beam models are not that much more money, and then you have the narrower beam if you want / need it.

I used to have dual beam units but never used the narrower beam, my last several units have been 200 khz only.

[solbes]

I'm interested in the answer too, since I will be upgrading my transom graph in a year or so.

And it also brings up a question I've had in my mind. Right now I have a dual freq. And I fish primarily on a lake with irregular breaks that can change depths very quickly. Most of the fish are on outer weedline in 16-22 feet.

Last year I ran it at a wider cone angle so I would have a better chance of marking fish. But if I'm understanding how it works correctly, the narrower cone angle would be more accurate to the actual bottom depth directly below me. Disadvantage being I will mark less fish with smaller cone. Is this thinking correct? If so, I would could troll more accurately with the narrower beam.

[SM1]

Solbes I’m thinking you are correct. The way I understand it is(someone please correct me if I am wrong) the higher frequency signal(i.e. 200kHz) gives a more narrow "cone angle" and a lower freq (i.e. 50kHz) gives a wider cone angle.

The 200 then gives more detail over less area where the 50 would give less detail over more area. The lower freq also does better at penetrating deeper water. I was told, when using a 200kHz you will see an area about 1/3 of your depth. So, for all you math whiz's, in 30ft you will see about 10ft circle. (and in 12ft only a 4ft..not very much)

For fishing walleyes in 60 ft or less, I would think a 200kHz would be everything you need and then some. However, I do think running a split freq screen would give you a better idea of what’s happening down there. I am looking to upgrading to a dual freq 200/50 ducer for that purpose and for better tracking of rigger balls at depths of 100ft+ (more for salmon, not walleye). My main unit is a LCX27, which has dual freq capabilities but only came with a 200kHz skimmer transducer.

[Cicada]

I'm not 100% positive, but I think kHz measures power put out by the unit and the cone angle is measured in degrees. Dual frequency may have more to do with rejecting interference.

When you are reading your depth finder, the number of feet it tells you you are at is the shallowest reading it decifers. For instance, if you are on a flat and it reads 30 feet of water, it is pretty close. If you are along a steep break where the bottom falls from 30 feet to 40 feet within the cone angle, you might be in 35 feet. This would have to be a very steep drop since you are reading about a ten foot difference within a ten foot circle.

I thought about this a minute and "googled" how a fish finder works. The top result of that search gives a pretty good tutoral about how these things work. I think I'm partially correct, but check it out.

[canman]

Thanks for the help. The 200khz will be all I need.

[PerchJerker]

The lower khz (ie. 50) will have a narrower beam, so if you're on a steep break you will have less of "dead zone" with the 50 than the 200. But in 16-22 feet you're not talking about a very big difference in the cone size. I still prefer the overall performance better with the wider beam 200 khz ..... but like I said earlier, the dual beam models are not much more money so if you think you might want to use the dual beam it's not a big deal to get it.