summertime vex.

[splash]

I,ve mounted my FL-18 on my pontoon for the summer.I keep it on one lake.I,ve encountered a situation of "interference" that has me baffled.With the bottom lock or auto zoom on,high or low power on,it looks like i'm sitting on a weedbed 6-10 ft. off the bottom but there are no weeds at all over the 15-35 ft. i fish.It kind of comes and goes but is there 90% of the time.I've hooked it up to the porta-pac power and trans. with the same results.ANY sugestions or comments would be appreciated. SPLASH

[Webguy]

Try the unit off the front of the boat away from all other power making sure the transducer is totally submerged and see if you get the same readings. If you do it may be the unit is failing, if it works OK up there then you had it in a bad location.

[Mudbug]

Call Vexilar, they had a problem with the electronics. A bunch of FL-18's of a certain vintage had a problem of the bottom bouncing up. I had one. Vex repaired it for free. They know by the serial # if the unit has a problem. Mine started acting up after the 2nd season of use. The first time it happened, I thought I was in a huge school of fish. Mine seemed to act up more when the battery was low on charge. I use my Vex-18 in my StarCraft, I have 3 deep cycle batteries, used for various duties on board, and since the repairs, the bottom hasn't bounced up, no matter how much interference is coming from the batteries, or how much junk I'm powering off the cells.

[Mackdaddy21]

Try running it on lower power (lp) mode. Just cycle  through the intereferance rejection by pressing on the gain nob. If these things don't work, and I'm sure you probably already tried them, it's a problem with the machine. Unless your operating a lot of other electronic devices (cell phones, motors, Gps) around the depthfinder, the problem lies soley in the machine.

Tyler

[fozsey]

Mine will totally make my hummingbird LCD useless. It won't find bottom, it wont find top, it says I am in 276 fow and then go to 0 and stay there. No fish marking either. Shut the vex off and just like turning on a switch...everything is normal again. I am not running off my boat either. I use it as a portable just like ice fishing.

[Fishingking]

my buddy and I both have a fl18 and sometimes we both get interference  that looks like air bubbles coming up from the bottom its always happened at night after the crappie bite slows down we always blamed it on  copepods and rotifers i nthe water column

[splash]

thanks evryone-nothing worked,sent the unit yo vex. they say unit is ok i am actually seeing something down there-dont know what.Told me one of the linder bros. wrote in fishin facts when freshwater shrimp come out around dark the vex. appears about the same way and they shut it off cannot use for showing fish in that depth?

[Skiff]

Splash - the nighttime fuzziness in some lakes is indeed a mass of bugs coming off the bottom.  They're called phantom midge larvae (Chaoborus) that look like mosquitoes in the adult stage, but don't bite.  They start to travel towards the surface at dusk, and you can see them rising on your fishfinder because each one has two air bubbles for buoyancy, and each bubble will return an echo to your fishfinder.  Even though they're only a half inch long, there's so many of them they can blot out anything under them.  A biologist I knew used to do vertical plankton net hauls at night, and he could tell where the midge larvae were in the water column, both by his depth finder and his net hauls.  During the day the larvae are at the bottom.