Topic: Double, triple, quadruple, ... depth readings. Power output.

[frstbubble]

I have a 998c HD  SI and have a XHS 9 HDSI 180 T transducer on it. In shallow water less than 5 feet I keep getting erroneous depth readings. I have tried changing 83kHz sensitivity, surface clutter, and changing between 200 and 83 kHz modes but still getting the bad readings.

My question is my 698Ci HDSI came with a XNT 9 SI 180 T and that unit is only 500 watts power. The 998 came with the XHS 9 HDSI 180 T and is 1000 watts power. Is the power the transducer puts out limited by the transducer or the control head? The lake my boat is on is an average depth of 15ft and I don't need (or really want) the 1000w power. My 2D graph is cluttered bad even in clear mode most of the time. I was wondering if I change to the non HD transducer (800kHz isn't effective in this shallow of a lake) would the power output be lower.

If the transducer can't reduce the power output then is there a way to reduce the power output on the unit?

Thanks for the help.

[rnvinc]

The power output is automatically adjusted by the unit dependent on how hard the unit works to find bottom ... (Deeper water requires more power) ... It cannot be manually adjusted ...

Multiple bottom echoes are a result of the sound pulse reflecting off bottom to the surface ...and then reflecting off the surface toward bottom for another trip to the bottom and back to the xducer ...

*Set the "Max Depth" setting under the Sonar tab to 20ft below any water depth you should ever see ...
*Set Switchfire to Clear Mode ...
*Set the Beam Frequency to 200kHz/83kHz to slow down the 200kHz ping transmit ...
*Adjust Sensitivity down ...

This still may not completely stop multiple bottom echoes ... Especially over very hard bottom...

Rickie

[frstbubble]

Thanks  rnvinc! I will try the max depth setting. I also will keep it on the 200/83 khZ setting. I did change that in past trying to get it to start reading correctly without success.

[tschultz]

Turn surface clutter up to 10 in shallow water not 8 or 9, turn it to 10.  That is your best chance at reducing the multiple pings.  Changing sensitivity isn't going to help you much in that regard.  That said transducer placement also plays a big factor in how severe multiple pinging may happen, as well as bottom content.  Clay seems to not play nice with multiple pingings for some reason.

[ITGEEK]

Actually, 1 is the most filtering, and 10 is the least.
I used to think it was the opposite, but Humminbird Greg confirmed.

Hey frstbubble:
How do you like your 360?
Any big dislikes?