OTS DRS-100 Mod B User Manual page 7

the optional EXT-24 external power supply (p/n 910091-000) (115 volts AC
input to 24 volts DC output) (+ red, – black).
8. Hydrophone VOLUME: Clockwise rotation past the detent turns the unit
on, indicated by the green "PWR ON" LED's (#3) illumination if the battery
condition is good. This knob controls volume to the front-panel speaker. All
sound in the water within range will be amplified through this speaker. Rota-
tion clockwise increases, and counterclockwise decreases, listening volume to
the front-panel speaker. Full counterclockwise rotation past the detent turns
the DRS-100 off.
9. Housing Relief Valve: This valve automatically equalizes internal pressure
during air travel.
10. Front-Panel Screws: There are ten Phillips screws located around the front
panel. Each screw has its own o-ring seal. When removing the screws and
front panel, ensure that you do not lose or damage the o-rings. Tighten the
screws only enough to ensure the panel is sealed against its o-ring.
11. LINE IN: This RCA jack allows the operator to transmit an external audio
source into the water (e.g., cassette recordings or inputs from a master public
address system).
12. Front-Panel Speaker: The front-panel speaker is used to listen to any un-
derwater sounds within range (e.g., biological or from human activity). The
hydrophone volume control (#8) adjusts the listening volume.
13. Handle: You will find two handles on the front panel. Use these to remove
the front panel after the ten front-panel screws (#10) are removed.
14. TONE/RECALL: When this toggle switch is pushed and held to the left, the
unit will emit a continuous tone, while the Tone/Recall LED (#4) illuminates
red. Push and hold the toggle switch to the right for the DRS-100 to emit an
intermittent tone, indicated by green illumination of the same LED.
15. MIC.: This jack is used to connect an HSM-10 hand-held microphone to the
unit. Voice transmission can now take place via the hand-held microphone.
Without the hand-held microphone, voice transmission can be accomplished
via the front-panel speaker (#12) and PTT button (#16).
16. PTT: This is a push-to-talk (PTT) control. When the DRS-100's power is
on, the user can depress and hold the PTT button and talk into the front-panel
speaker. His voice will be received by all divers within range. The volume
to the divers is controlled via the transmitter volume control (#17).
17. Transmit VOLUME: This control adjusts the volume to the divers. Rotation
clockwise increases and counterclockwise decreases the volume. Generally
three fourths of a turn clockwise is the best position.
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