Adjusting the output power to match varying conditions
You are permitted to adjust the output power from the ST90. Tx Power is used to control the amount of power that is transmitted with each ping.
Context
Most users operate the ST90 with Tx Power set to Maximum. This allows for maximum range, and works well in open waters with sufficient depth. Certain operating conditions may make it appropriate to adjust the output power. Use Tx Power to reduce the transmitted acoustic energy compared to the maximum output.
Tip
If you work in shallow and/or confined waters you may find it useful to reduce the output power to avoid reverberation.
Some of our users claim that reducing the output may be useful if you are looking for scattered fish.
If you operate in the close vicinity of other vessels that are also using the ST90, interference may cause problems. Reducing the output power is not a practical way to deal with interference. It is more efficient to change the operating frequency.
To investigate unknown and/or unfamiliar targets, some user prefer to "reset" the ST90 by turning off all the receiver filters and adjust the output power.
Sea conditions vary, sometimes drastically. The acoustic conditions are also changing. Temperature and salinity layers differ from one day to the next, and from one position to another. It is not possible to identify settings that will provide the best data at all times.
Procedure
1 Open the Operation menu.
2 Select Tx Power.
Image
3 Select the requested output power.
Select either side of the button to choose a value.
Select the middle of the button to open a small menu with the available options.