Fishfinder not reading more then 200ft :(

[babalaza]

Having trouble with a Furuno LS4100 fishfinder (yeap old and cheap). It has a transom mount transducer. Works fine until 200ftf, after that it starts blinking and the depth goes up and down like crazy.

Anyone has a clue on whats going on?

Prop wash problem? Transducer too close to the motor? should it be "deeper" into the water?

Thks for any suggestions

[gottaflylee]

What frequency are you on? 200kz is for shallow depths and 50kz is for deeper depths. Also your transducer may not have the power to read deeper. Is this something new, were you or have you been able to read this deep before or are you venturing out to that depth for the first time?...

[babalaza]

howdy Capt. Lee, I need to check the frequency then. lol sucks to be a noob in fishfinders. I remember playing around with the frequency on the shallow wrecks but never bothered to mess with it in outer waters. Been fishing deeper for a few times, just installed the 4100 hoping for the better! 200ft was the break line of the fishfinder going insane though. If its not the frequency, what can it be?

[joeksr]

howdy Capt. Lee, I need to check the frequency then. lol sucks to be a noob in fishfinders. I remember playing around with the frequency on the shallow wrecks but never bothered to mess with it in outer waters. Been fishing deeper for a few times, just installed the 4100 hoping for the better! 200ft was the break line of the fishfinder going insane though. If its not the frequency, what can it be?

Well.
Do you have a dual frequency transducer and is your unit for deep water ? Is there a setting for auto select for frequency and did you "choose" the frequency when messing with it ? Sensitivity, lots of settings can throw it off.
Check the directions.
I know I know, real men don't need no stinkin directions but check em anyway.

[babalaza]

yeap the transducer is dual frequency. Must have have changed it to 200hz while playing with it, I remember noticing more details on one then the other and leaving it that way. I'll get a friend to check the auto thing as I am away from it now.

And yeah you right.. directions? what is this thingy? I blame the wires connections *cough cough*

*# Seven depth scales, from 0-10 to 0-640 feet
# Depth offset to 1,500 feet, maximum depth scale of 3,000 feet

should be able to read, no?

[clt_capt]

I have a larger Furuno unit, and I have noticed that when the range is in manual mode, and I am deeper that the unit is set for, readings are very erratic... - ie: range 200ft, actual depth 400...

You might try checking your range...

[joeksr]

yeap the transducer is dual frequency. Must have have changed it to 200hz while playing with it, I remember noticing more details on one then the other and leaving it that way. I'll get a friend to check the auto thing as I am away from it now.

And yeah you right.. directions? what is this thingy? I blame the wires connections *cough cough*

I hear ya. Got a new unit myself and am working on how to figure out how it works. Reading directions just dont seem right.

[ElMar2530]

Just a guess but check to see if there are any barnacles or growth on the transducer, Mine starts to loose it about now then I dive in and scrub and she's good to go for the rest of the season.

Just a thought, good luck.

[ultangler]

Betcha dollars to doughnuts, the problem relates to a sensitivity setting, not the frequency--200khz should work just fine clear down to 400' or 500'. Switch to 50khz in 200' and detail level will drop dramatically without any benifit. It's not range related, either, or the unit wouldn't start blinking (which means it's lost touch with bottom.) Make sure sensitivity is set to auto, and if it already is, go to manual and juice it up.