Vertical "lines" on bird screen

[Bigfishhunter]

I am sure this has been discussed, but when I did a search with the words vertical, lines, and sonar, I got a lot of hits that weren't really related, and my brain is too tired from fishing to think of other terms to use.

I was fishing a lake trout tournament this weekend, and had some issues with my sonar. I would get these vertical lines or gaps in my readings of the graph. THis would be very magnified in the deeper water that we were fishing in (90-110 FOW). Most of the time we were anchored and jigging, and this made it much more pronounced. If I trolled or was moving to find fish it was clearer, but when I was stopped and directly vertical, it was not as clear. It was not as noticable on the regular display, but I often fish with split screen with the bottom on 4x or 6x magnification. I did at times lose bottom, and my graph would read 10 feet, or 0 feet, when I was fishing in 100 FOW, and hadn't moved. The only way I could get it to read bottom when it did that was if I dropped the anchor, it would grab hold of the anchor, and follow it till it got the bottom, or I would set the bottom limit to read just below, what I knew I was in, that worked too. I also lost bottom a few times cruising around.

My question is..... Would a new transducer solve this problem. My current ducer does have a few dings in it. Probably from rocks and things. I have started to trailer with it in the up position, but for a few years I had that screw in it so I couldn't tilt it up.
Or, do you think it might be a cord or connection problem? I did remove the screen and reatach it to the mount, but that didn't seem to help.
Anyway, thanks for the help.

[Jason Halfen]

If you have physical damage to the transducer, which it sounds like you do, then you should definitely expect reduced performance relative to your expectations. No mount of tweaking the display settings will compensate for a transducer with nicks and dings.

[Bigfishhunter]

makes sense, I kind of figured that. Guess I will be getting a new transducer.

[LWinches]

Vertical lines and gaps can sometimes show up when the unit is confused as to where the bottom is. Hummingbird and Lowrance use a ping algorithm that requires first knowing the depth accurately. On a Lowrance I can set the ping speed manually. Hummingbird uses a ping speed algorithm that works great as long as it knows the depth and you're not in 150 FOW. You may have noticed that in 150 FOW you get bands of mystery dots on the screen. I've used several Humminbirds and every one of them got goofy from 150-170 FOW. If you turn the sensitivity down enough to clear it up it won't show the fish. I've complained about this for years with no response. You can help it out some by setting the Max Depth to 170. It's just my opinion but it looks exactly like what I would expect if the ping speed was too fast for the depth. Otherwise (at other depths) I love the fast ping speed. Judging from the response time of moving a jig up and down and watching it on the screen for the length of delay, the auto ping speed of Hbird is faster than the auto ping speed of Lowrance in deep water.

On losing bottom: I fish 100 FOW or more regularly. I've had the same problem with Humminbird and Lowrance and a number of units of each brand. Mostly for me these problems were caused by a bad combination of adjustments and water characteristics. I like to run sensitivity high. In deep water this will sometimes make the returns from surface clutter stronger than the returns from the bottom and if the unit is set on auto depth whamo it thinks you're in shallow water. Generally now I do not run auto depth or auto sensitivity. I set the range manually to give me a satisfactory look at the bottom and then run the sensitivity whereever I want. Also I frequently use the advanced options to limit the range to the depth range that is most reasonable. When I already know that the fish are 100-110' deep I really don't need to even look at 0-60 so I may set the range to be 60-120.

Hope this helps. Not really kicking either brand. I use both.

[Bigfishhunter]

Using a set depth range really does not cut it for me and for lake trout fishing. This time of year, they literally can be anywhere in the water column. I caught a bunch of fish on the bottom in 110 FOW, then marked a big ball of baitfish going by at 40, with arcs all over them. I reeled up to that ball, and bam got a fish. If I would have had it set with a top limit, I wouldn't have seen those. The depth changes on the lake that I fish are so drastic that I really appreciate having an auto depth adjustment.

[1625rebel]

Just want to make sure this isn't an interference issue. With my HDS 7 being so darn sensitive, I get vertical lines any time someone else gets within 75-100 yards of my boat. Even more so if they have one of the higher power Lowrance/Bird units of a few years ago. Those units shout out the pings with power to get a good return signal. The HDS whispers its sonar pings and hears them quite well. The result is vertical rain on my display until our boats separate.

Also, I'm hoping this is not related to power source (i.e. its not on trolling motor battery). And that you are not using two units on the same boat with the same frequency. I get lines when I use the bow and console at 200 kHz.

Probably none of these issues, just wanted to make sure its not the basic stuff. I only fish to 80 FOW so haven't been that deep yet.

[LWinches]

1625Rebel,

You are so right. I an constantly amazed at how far I pick up signals from another boat.