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I'm fishfinder-dumb. Help me understand?

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I'm fishfinder-dumb. Help me understand?

Old 07-26-2013, 07:41 PM
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Default I'm fishfinder-dumb. Help me understand?

I have a Standard Horizon CPV-350 multi function unit, and an Airmar P-58 transom mount transducer; recently installed on my boat this season, and am still getting used to it. I'm not an avid fisherman, but still like when things are set up and working as they should.

I have my gain set to 7%, depth range set to auto, 200khz. The deepest parts of Lake Erie where I'm at don't approach much more than 40-50'. Keel offset of 1.5'.

The screen shot below was taken earlier today at a marina. Most likely some algae type growth on the bottom, sand/silt/mucky base. Could someone tell me in semi-easy to understand terms what my screen is telling me? I understand the reddish line near the bottom of the screen is the bottom profile, but what about the data near the top of the screen? I understand the scale off to the right is the depth range, but what about the extreme right hand side of the screen...what am I looking at there?

My cruising speed is mid 30mph range, and by that point, it becomes a blur and the depth jumps all over the place. I'm sure my transducer could use a bit of adjustment and is just picking up cavitation or something while on plane. No HUGE deal here.

What settings SHOULD I be using for my area?

Also, I have the NA-M026 chip in the GPS and am getting used to the settings on that too. When I have the display zoomed in; enough to pick up channel markers, etc, it is CONSTANTLY refreshing, and making things hard to focus on. I have tried to change the frequency of the track plotting, but not sure what that SHOULD be either.

Thanks for any help!


Old 07-26-2013, 08:06 PM
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I'm just as confused as you.
Subscribed.
Old 07-26-2013, 08:42 PM
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Originally Posted by Albert Jr. View Post
I'm just as confused as you.
Subscribed.
A "fishing addict" would never be confused by a sonar.
Old 07-26-2013, 08:45 PM
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Originally Posted by paragod689 View Post
A "fishing addict" would never be confused by a sonar.
One who has never used electronics would.
Old 07-26-2013, 09:02 PM
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The color on the far right of the screen is the amplitude scope. It basically previews the returns before they are displayed. It shows the amplitude of your return echoes in real time. If you pause the screen the amplitude scope will continue in real time. I turned mine off.
Old 07-26-2013, 11:33 PM
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Originally Posted by mulletblaster View Post
The color on the far right of the screen is the amplitude scope. It basically previews the returns before they are displayed. It shows the amplitude of your return echoes in real time. If you pause the screen the amplitude scope will continue in real time. I turned mine off.
Yes, commonly referred to as the "A-Scope" . It's what is being detected presently in the sonar beam cone. Whereas everything to the left is historical graphics of what you have already passed over & generally easier to comprehend in continuous archival flow . If your boat is moving forward , everything on the screen to the left is area moving aft in your wake, But I expect you get that part. .

I suggest you leave depth range on auto but if possible zoom in if fishing lower in the water column, and use manual gain much higher off the dock in deeper water until excess noise is displayed then back gain off for clearer screen but showing strong targets. 7% gain is quite low, but you were in only 12' depth.

The 200 kHz setting with 11* beam angle will give you best sensitivity and target discrimination when searching for fish, but the 50 kHz setting with 45* beam angle would best help basic hunting for specific structure to the sides of your boat path over ground. But it's still just a 600 watt T/D, fairly adequate for your shallow Erie depths. The P-58's 24-30 "Q-factor" ( essentially excess T/D "ringing' after the intended pulse) will generally leave a substantial near-surface segment of the water column unavailable for target returns. That's probably most of what you see on the screen near the surface, and it will increase as you increase gain level. Most fishfinders have a Surface-Clutter adjustment that will allow to blank out that clutter if you wish, but any targets (fish) in that surface segment will still not be discerned on your screen.

http://www.airmartechnology.com/uplo...ochures/p58.pd

I'm not familiar with the plotter but if by any chance you have it set on Course or Heading Up chart mode , you might try North Up mode for much more stable charts with minimum updating. But note some chartplotters (like my now very old N/S 952XD) have very fast processors for near-instant chart screen refreshing, while some others's slow processors are just always tediously slow to update the view.
Old 07-27-2013, 12:01 AM
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Originally Posted by IcutMetl View Post
I understand the reddish line near the bottom of the screen is the bottom profile, but what about the data near the top of the screen?
That is just surface clutter, i.e. noise. So you can ignore it.
Old 07-27-2013, 04:03 AM
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Originally Posted by TTaxi View Post
Yes, commonly referred to as the "A-Scope" . It's what is being detected presently in the sonar beam cone. Whereas everything to the left is historical graphics of what you have already passed over & generally easier to comprehend in continuous archival flow . If your boat is moving forward , everything on the screen to the left is area moving aft in your wake, But I expect you get that part. .

I suggest you leave depth range on auto but if possible zoom in if fishing lower in the water column, and use manual gain much higher off the dock in deeper water until excess noise is displayed then back gain off for clearer screen but showing strong targets. 7% gain is quite low, but you were in only 12' depth.

The 200 kHz setting with 11* beam angle will give you best sensitivity and target discrimination when searching for fish, but the 50 kHz setting with 45* beam angle would best help basic hunting for specific structure to the sides of your boat path over ground. But it's still just a 600 watt T/D, fairly adequate for your shallow Erie depths. The P-58's 24-30 "Q-factor" ( essentially excess T/D "ringing' after the intended pulse) will generally leave a substantial near-surface segment of the water column unavailable for target returns. That's probably most of what you see on the screen near the surface, and it will increase as you increase gain level. Most fishfinders have a Surface-Clutter adjustment that will allow to blank out that clutter if you wish, but any targets (fish) in that surface segment will still not be discerned on your screen.

http://www.airmartechnology.com/uplo...ochures/p58.pd

I'm not familiar with the plotter but if by any chance you have it set on Course or Heading Up chart mode , you might try North Up mode for much more stable charts with minimum updating. But note some chartplotters (like my now very old N/S 952XD) have very fast processors for near-instant chart screen refreshing, while some others's slow processors are just always tediously slow to update the view.

Thanks; guys, for the replies. I will try playing with the manual gain some more, as well as the surface clutter filter. I'm not too concerned with fish at the surface level anyway. I noticed as I decreased the gain, the bottom started to look more mushy...if that makes sense.

I will also try the North Up mode; I have taken some time to become familiar with the menus, but haven't explored all the options. I had a little Garmin 178c on my last boat; and while much smaller, it let me zoom in while I was coming back into port to the point where I could see the markers, hazards, etc show up on the chart, without the screen constantly refreshing. It just drives me nuts; and if I have to be zoomed way out all the time, it somewhat defeats the purpose for me.

Now that I've done a little more reading in the manual, I understand what the A-scope does- I may try to turn that off.

Regarding the 50/200khz, the reason I had it set to 200 was because the manual said it would be better for shallower waters...Lake Erie is pretty damn shallow compared to some of the areas the rest of you guys are in.

One thing I did discover; I have my keel offset set to +1.5', which I think is why the surface clutter appears below the very top of the screen. It should actually be set -1.5' according to the manual.
Old 07-31-2013, 02:24 AM
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I got a chance to play with my FF a bit more last night. Found out how to turn my A-scope off. Did not mess with surface clutter/filter settings, only know that the filter is ON.

Was in same marina at first; keep in mind it has a bottom that is full of tall, loose growth in the slip I was in.

Keel offset to 0.0', 50% gain, and settings as shown on screen-


Gain backed off to 20%; seems to be showing the growth a bit more.


White Line turned on; full zoom on left pane. Didn't see if I could adjust the zoom view at all.


Full screen; no zoom.


Same settings as above; coming back into the bay where my marina is


Coming thru the marina on way to my slip.



Also experimented with the GPS a bit more; tried NORTH-UP, but me no likey. Hope to be able to play with it a little more each time until I get used to its quirks. Certainly not as friendly as my old Garmin, but much more adjustability.
Old 07-31-2013, 06:45 AM
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Rick huckstepp's depth sounder secrets book would probably be of assistance - I've not read it myself but it seems to be well reviewed.
Old 07-31-2013, 03:50 PM
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I have started to collect useful videos on fish finders (among other boating/technical topics). Here is a starter set that might be useful to learn the basics: http://www.whatsbestforum.com/showth...d-fish-finders

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