Marine Electronics Forum - Sonar question: What does the red mean?

On a Northstar 660, I am getting a large red uneven band at the top of the screen (that would be read as closest to the transducer) that follows uneven contours often half the way down the screen to the bottom. I have tweaked every setting I know to not see it with no changes. What does it mean? Of course..the documentation does not tell how to read it or what it is.

Is it water temp? Noise? (all the noise filters are turned on). It is, AFAIK, correctly reading the depth and the bottom contour. It does this on 50, 200 and 50/200 khz mixed. The red is seen in the white pallet, but it is seen in different colors in all pallet choices.

I upgraded from a Northstar 657, and also saw it with that one, but am using the same trandsducer.

If this doesn't make any sense, I'll try and get a pic tomorrow.

If you do get a pic I'll compare it to what's on mine. Have you tired the gain also?

on my garmin that is surface noise and can be filtered out by selection (show/hide surface noise). are you certain you turned the filter on?

Elyse is right. You are most likely seeing surface clutter. There is generally a setting on FF to adjust the STC control for short, med, or long (or off). You may need to fiddle with that to get the display as you like. In very shallow water, you probably will turn is off. In deep water, set it to med or long. What it does is reduce the FF sensitivity on echos comingback from the near the surface, but allow increased sensitivity for echos returning from deeper water. At least that's how I remember it working. Unless youare very interested in the water column right under the boat, you can basically ignore that band of red near the surface, and just look at the depths you are most interested in.

Maybe someone else can explain it better, as I never had a Northstar FF to begin with.

On my Furuno some of the filter options are only changable by turning off the machice and then turning it on while hitting certain keys. Maybe your not seeing the menu you need with the unit on.

Here you can see the red I'm talking about. Northstar has a choice of gain: Cruising, Fishing, or manual. This is cruising. If I go manual and turn the gain down much, it loses bottom and depth.
http://www.thehulltruth.com/members/joe-albums-northstar-electronics-picture40916-lots-red.jpg

Here are the filter settings.
http://www.thehulltruth.com/members/joe-albums-northstar-electronics-picture40917-all-filters-cut-gain-set-cruising.jpg

Red is usually indication of hard bottom. My first guess is there's way too much gain. You cannot control range and gain on this unit w/o losing bottom?

IMO, avoid automatic settings. Furuno advises against them saying "Auto is useful when one is busy w/other things, ie: negotiating a narrow channel or busy harbor"

If I go manual and turn the gain down much, it loses bottom and depth.

What happens when you turn that noise filter off or low, and the receiver filter set to off or narrow?

Nothing really. None of those pictured seem to have much effect..accept to make it worse.

Where's the ducer mounted?

On my maching i have a "surface clutter" option to increase or decrease as i like with 10 setttings. If i put it on setting #1 there is no surface clutter at all but this also makes my maching less sensitive to see other things so i have it set to see a little surface clutter. Thats way too much clutter on your machine. There has to be a setting for it.

If you dropped a jig or bait down right under your ducer can you see it??
Id try that first to see how sensitive your ducer is. If you can id then turn down the sensitivity or gain and see if the clutter goes away while still being able to see your bait. Also some units have a salt/freshwater mode. The unit will be slightly more sensitive in freshwater mode.

Transducer is transom mounted.

I haven't tried the jig under the 'ducer yet. I'll try that and see if I can see it.

Anyone else got one of these?

i also have a northstar 660, with trans mount ducer(soon to be upgraded). althought i typically fish a little deeper i too experience that "red band".
several calls to northstar, airmar, and more importantly to local "gurus" in sonar have explained to me that the red is the main bang of the signal reflecting immediately below the ducer. i never use the auto functions in regards to the "sonar" they filter out too much of what i am looking for. in the past 2 years i have learned quite a bit about the 660. i will review my settings and post them if interested. keep in contact so that we can compare what works and what doesn't. best of luck.

It appears to me, from your pic, that you may have the depth set at 20 feet or you are set on auto depth. My question to you is; "What do you expect to see on the surface?" After all your boat will scatter anything alive in the top 4 to 6 feet so really, what do you expect to see? If you have the unit zoomed IN, go ahead and zoom OUT and that should slim down that red area. Or maybe adjust the depth to deeper.

I never have been a fan of LOW - MEDIUM - HIGH type of adjustments because it seems there is too much in between that you could control. Same with ON/OFF. If it can be turned ON it should have an adjustment. Another thing to remember is if you are running in MANUAL mode, every filter you turn on, somewhat defeats the MANUAL mode purpose. Those filters are already turned ON in the AUTO mode.

Remember that what is in the top 4 to 6 feet of water is pointless. If it is alive, it's already gone before your XDCR gets there, and if it is a log, you've already ripped a hole in your hull by the time your DXCR gets to it.

Edd

i also have a northstar 660, with trans mount ducer(soon to be upgraded). althought i typically fish a little deeper i too experience that "red band".
several calls to northstar, airmar, and more importantly to local "gurus" in sonar have explained to me that the red is the main bang of the signal reflecting immediately below the ducer. i never use the auto functions in regards to the "sonar" they filter out too much of what i am looking for. in the past 2 years i have learned quite a bit about the 660. i will review my settings and post them if interested. keep in contact so that we can compare what works and what doesn't. best of luck.

That would be great! I'm going to play with the manual settings some more and see what that gets me. I'll post back here. Would you do the same?

As you know, N* tech support is close to worthless. It seems like if you want anything done on these units..you have to do it yourself.

It appears to me, from your pic, that you may have the depth set at 20 feet or you are set on auto depth.

The range is set to auto.

My question to you is; "What do you expect to see on the surface?"After all your boat will scatter anything alive in the top 4 to 6 feet so really, what do you expect to see?

I dunno..I guess I expect to see whatever is there. With it red like that, a blue whale could be underneath me, and unless he's read and shaped like an inverse bottom contour, I won't know anything about it.

If you have the unit zoomed IN, go ahead and zoom OUT and that should slim down that red area. Or maybe adjust the depth to deeper.

Actually, I have found that does work, but I haven't had a chance to try it out yet. Seems like I'm going to lose half my screen for use (or more) though doing that.

I never have been a fan of LOW - MEDIUM - HIGH type of adjustments because it seems there is too much in between that you could control. Same with ON/OFF. If it can be turned ON it should have an adjustment. Another thing to remember is if you are running in MANUAL mode, every filter you turn on, somewhat defeats the MANUAL mode purpose. Those filters are already turned ON in the AUTO mode.

Well...it is what it is.

Remember that what is in the top 4 to 6 feet of water is pointless.

Certainly there is a way to tune the thing to see skinny water better than that.


If it is alive, it's already gone before your XDCR gets there and if it is a log, you've already ripped a hole in your hull by the time your DXCR gets to it.

Edd

The boat and engine only draft about 2 feet of water..so that's not exactly true. And how about if I'm just floating? I've caught fish in skinny water before just floating..haven't you?

The range is set to auto.

Try changing this to as close to the depth you are actually in. Do you really have FEET in that unit or is it something like SHALLOW - DEEP - DEEPER ?
Note here.......If you are in MANUAL mode, you'll need to adjust your sensitivity/gain when you change depths.

Tip: A simple way to get correct gain is to select double the depth you are actually in......adjust the gain just until you start to get a second echo, then set the depth to your actual depth.


Actually, I have found that does work, but I haven't had a chance to try it out yet. Seems like I'm going to lose half my screen for use (or more) though doing that.
That's how you learn.



Certainly there is a way to tune the thing to see skinny water better than that.
Calibration is calibration. If you have choices of LOW - MEDIUM - HIGH that's what you have. The higher end units have a 0 - 100 calibration scale which offer much more options. I lose ONLY about 2 feet in noise when I'm in as shallow as 8 feet of water that is stained.


The boat and engine only draft about 2 feet of water..so that's not exactly true. And how about if I'm just floating? I've caught fish in skinny water before just floating..haven't you?

Lets find out what type of XDCR you have and where it is mounted. BUT! What I said is TRUE. Now if you want to float and fish you simply adjust the gain down and the depth to as close as you actually are. Turn the noise filters off at first because if you are floating you probably don't have any noise to filter.

I'm a Lowrance user because I can tweak my units more precisely than LOW-MED-HIGH, but I also must deal with other Lowrance issues.

When it comes to sonar you sort of need to dance with who ya brung....if you get my point.

I love sonar so I'll try to help you however I can....PM or email.

Edd

Here's a screen shot from another thread that will help you see what I am talking about.

http://i258.photobucket.com/albums/hh252/eddallen/shot11-1.png

You can see that the top 2-4 feet is unreadable. But you can absolutely see fish in the SKINNY water. I think you may have something out of tweak and if you keep fiddling with it you will work it out.

Edd

hey joe,
more than glad to share info with you and vice versa. my typical depths i fish in are 5 to 150 feet. out here on the west coast i am concered more about conditions in skinny water than what my meter reads, in fact at 5 feet i shut down the sonar when i come tight on the anchor. deeper depths i obviously leave it on. sorry i do not have any pics for you but i will work on that. my settings that i currently use are as follows:

range auto when in transit, manual in near vicinty/on the spots
200khz
gain 18
threshold 30-41%
scroll speed very fast
symbols no fish symbols
fish filter small
fish sensitivity high
digit size med
depth "check mark"
color ""
zoom ""
palette blue
interference filter no
noise filter no
pulse short
power high
receiver auto

50khz
gain 13-15
threshold 11-15%
pulse long to track fathom curves
all others the same

of course these are vary due to temp/salinity.... you know the deal
as a note i too have a few feet of interference due to "main bang" on suface clutter however as mentioned in recent posts at 3 feet in 200khz i'd be looking at something like 3 inches which really isn't helpful.
also never have seen an arch like manual depicts although i suspect those screenshots are more for marketing.
keep contact so we can compare/contrast notes.
best of luck.

Joe,


I have 2 Northstar 660/Navman 6600-same thing.

http://i11.photobucket.com/albums/a184/thundra04struck/Guagescruise.jpg

You can see the condensation/fog on the inside of the screen in this shot. Once I stopped keeping the lid/the white covers on the units, I have never had the issue again, it was also part of the reason why I got another unit for nothing, YES!

In this pic, you can see I'm at 164' and can see the red at the top of the water column, and some nice fish on the bottom-lock on the left side of the screen, and nice calm water and my wife on the bow too.

http://i11.photobucket.com/albums/a184/thundra04struck/FFLitUp.jpg

The 660-top unit is my dedicated sonar, hooked up to an Airmar B60 20-degree deadrise unit.

The 6600 is my dedicated GPS.

I know the "red line"/area you are talking about on your sonar display. I know that when I'm in water less than about 5'-deep, I get that red area and it is a solid red all the way to 15" which is what my boat draws with the motor tilted up.

At around 10', the red goes down from 2-5' and as I never expect to see anything/any fish at that depth, I have not tried to tune it out.

I was able to tune it out a fair bit today by changing the range to manual and changing the gain in 200Khz to 9, and in 50 khz to 4.