Just took my 1000 out of the box. All excited to charge batteries and wouldn't you know it, Wrong charger. Anyway went and got some AA batt. for back up power pack and installed them. This is where I need help. The manual states I should hear steady hum, can someone guide me with first time use of this unit. What would you recommend that the control knobs be set at for first time use? I plan to use the 1000 on the beach (West Palm Beach, Florida) and no more than 25'underwater. I have set up a test area in my yard to get use to the unit, But I can't seem to find the tones. Thanks