Aquacom MK2-DCI User manual

User Guide
“Technology in Depth”
Two- or One-Diver Intercom
AQUACOM®MK2-DCI

- Notice -
This manual and the information contained herein are provided for the use as
a maintenance and operation guide. No license or rights to manufacture,
preproduce, and/or sell either the manual or articles described herein are given.
Undersea Systems International, Inc., dba Ocean Technology Systems, re-
serves the right to change specifications without notice. It is recommended
that all users read and fully understand this manual before using MK2-DCI.
All statements, technical information, and recommendations herein are based
on tests we believe to be reliable, but the accuracy or completeness thereof is
not guaranteed; and the following is made in lieu of all warranties, expressed
or implied, including the implied warranties of merchantability and fitness
for purpose: Seller’s and Manufacturer’s only obligation shall be to replace
such quantity of the product proved to be defective. Before using, user shall
determine the suitability of the product for intended use, and user assumes all
riskandliabilitywhatsoeverinconnectiontherewith.NeitherSellernorManu-
facturer shall be liable either in tort or in contract for any loss or damage,
direct, incidental, or consequential, arising out of the use of or the inability to
use the product. No statement or recommendation not contained herein shall
have any force or effect unless in an agreement signed by officers of the
Seller and Manufacturer.
- IMPORTANT SAFETY NOTICE -
(Please read before using product.)
IT IS ABSOLUTELY ESSENTIAL THAT ALL DIVERS ARE PROP-
ERLY TRAINED AND EQUIPPED AND FULLY UNDERSTAND THE
OWNER’S MANUAL BEFORE ATTEMPTING TO USE THE
AQUACOM®MK2-DCI.
WHILE AQUACOM®MK2-DCI PROVIDES DIVERS WITH GOOD
UNDERWATER COMMUNICATIONS, IT DOES NOT CHANGE OR
ELIMINATE THE POTENTIAL HAZARDS OF DIVING!
DO NOT ATTEMPT TO CHARGE BATTERIES BEFORE READING
PAGE 9, NUMBER 2, THE RB-6V SIX-VOLT OPTIONAL RECHARGE-
ABLE BATTERY SECTION. WITHOUT FOLLOWING PROPER PRO-
CEDURES, DAMAGE TO THE MK2-DCI, AN EXPLOSION, AND/OR
INJURY MAY OCCUR.
© Copyright 2001 Ocean Technology Systems
PN 506049-000 Rev. D

Table of Contents
Introduction (Section 1)........................................................... 1
MK2-DCI Specifications (Section 2) ...................................... 2
MK2-DCI Operating Instructions (Section 3)...................... 3-4
Figure 1 (MK2-DCI Two-Diver Air Intercom)........................ 5
Two-Wire Mode (Section 4) .................................................... 6
Two-Wire Mode (Figure 2), Four-Wire Mode (Figure 3)........ 7
Four-Wire Mode ...................................................................... 8
Batteries (Section 7) ........................................................... 9-12
Helpful Hints ......................................................................... 13
Limited Warranty................................................................... 14
i

SECTION 1
INTRODUCTION:
Congratulations! You have just purchased the finest, state-of-the-art
hard-wire intercom in the world. Your new MK2-DCI Two- or One-
Diver Air Intercom represents state-of-the-art technology and innova-
tion—the choice of discriminating divers throughout the world. Please
take the time to read this owner’s manual. With proper care and use,
your Ocean Technology Systems product will provide you with the ul-
timate in high-quality communications and reliability.
The MK2-DCI is a compact, self-contained Two- or One-Diver Air In-
tercom providing clear communications between the operator and
diver(s). The MK2-DCI offers two- or four-wire communications.
This manual will cover Specifications, Operating Instructions, Two-
Wireor Four-WireCommunications, Batteries,Helpful Hints,and War-
ranty Information.
These guidelines and illustrations are presented to assist you. If you
need additional information, do not hesitate to confer with your local
OTSdealer orrepresentative.If yourequireservice, contactOceanTech-
nologySystems,3133 WestHarvardStreet, Santa Ana,California92704,
Telephone [phone], Toll-Free [phone], Fax (714) 966-
1639, www.oceantechnologysystems.com.
1

SECTION 2
MK2-DCI SPECIFICATIONS:
BatteryLife: 20 hours continuous use
BatteryType: (2) 6-volt lantern batteries, recommended
batteries (Eveready Heavy Duty Alkaline
#528 or Duracell Heavy Duty Alkaline ID
#9150) or an external 12-volt source; op-
tional 6-volt rechargeable batteries.
Power Output: 20 watts
Frequency Response: 600 to 12,000 Hz
Cabinet Material: ABS plastic
Front Panel: 1/8” aluminum, chemically treated and
coated with a tough, durable, urethane fin-
ish to withstand the marine environment.
Size: Height: 6 5/8” (16.8 cm)
Width: 16 3/8” (41.6 cm)
Depth: 8 3/8” (21.3 cm)
Weight: 14.0 lbs.
2

SECTION 3
MK2-DCI OPERATING INSTRUCTIONS (see page 5):
1) Record Out: Permits tender to record diving operations (Line
level).
2) Volume: Tender-to-diver(s) volume control.
3) Power ON: Turns the power ON or OFF.
4) Battery Level: Color LEDs illuminate to alert tender to condi-
tions of batteries.
5) Ext. Power: A 12-volt, DC power source can be used.
6) Push-to-talk: Push button used in two-wire mode by tender to
talk to divers.
7) Tender Tender-worn earphones connect via banana
Headset: plug connectors.
8) Mic. (RED): Used for hand-held or boom mic. via banana plug
connector.
9) Volume: Diver #1: diver-to-tender volume control.
10) Earphone: Diver #1: earphone connection (banana or bare-
wire style).
11) Microphone: Diver#1:microphone connection(bananaorbare-
wire style).
12) Volume: Diver #1: tender-to-diver volume control.
13) Microphone: Diver#2:microphone connection(bananaorbare-
wire style).
3

14) Earphone: Diver #2: microphone connection (banana or
bare-wire style).
15) Handle: Front panel handle (right & left side).
16) Volume: Diver #2: tender-to-diver volume control.
17) Volume: Diver #2: diver-to-tender volume control.
18) Speaker: Front panel speaker.
19) Thumb Screw: One of four front panel screws (captive).
20) Speaker: Remote speaker output (speaker level).
21) Volume: Volume control for front panel speaker.
22) Speaker: Switch to turn the front panel speaker ON or
OFF.
23) Cross Talk: Switch used to cross-talk Diver 1 to Diver 2
or vice versa. Tender must hold the switch in
the directioin of the cross talk. This is a mo-
mentary switch.
24) Diver Select: Switch used to select Diver 1, Diver 2, or
Both-Divers communications.
25) REM: This connector is used if a headset/boom mi-
crophone with a PTT switch is used.
(Note: See page 5, Figure 1 for a panel description.)
4

MK2-DCI TWO-DIVER AIR INTERCOM
Figure 1
5

SECTION 4
TWO-WIRE MODE:
In normal two-wire operations, the two wires within the diver commu-
nication cable are connected to the corresponding binding post (Divers
#1 and #2) on the surface unit (see Figure 2). If a four-wire cable is
used, two wires are normally twisted together for one side of the micro-
phone binding post, and the remaining two wires twisted together for
the other microphone binding post.
This configuration allows the tender to talk to the divers individually or
both divers simultaneously. The diver(s) may also communicate with
each other when the tender engages the cross-talk switch. The divers’
speaker and the surface unit speaker both function as speaker and mi-
crophone. If required, a separate microphone and earphone can be used
with the divers’ masks or helmets. If a speaker is located in a diving
bell or recompression chamber, the MK2-DCI can be used as the com-
munications link between the divers and the outside. When the system
is used where conditions are noisy, the tender can switch off the speaker
and use a headset and boom microphone. However, when using a head-
set with a boom microphone, the tender must use a push-to-talk (PTT)
button to communicate. Our headset with a boom microphone has a
PTT button located on one side of the headset. The MK2-DCI also has
a PTT. The divers’ communication is the primary signal. When the
tender uses the PTT button, his signal becomes the primary signal. If
the diver is trying to say something while the tender is talking, the ten-
der will not hear the diver until he releases the PTT button.
The divers’ helmets and/or full face masks are typically wired with the
earphones and microphones tied together. When wired like this, the
divers’ earphone and microphones are functioning together. Bubbles
passing by the earphones while the diver is talking will be picked up
via the earphones. This will cause the communications to be noisy.
When the tender is talking to the diver, his voice is heard not only from
the diver’s earphone, but also from the microphone!
6

7
TWO-WIRE MODE (Figure 2)
FOUR-WIRE MODE (Figure 3)

SECTION 5
FOUR-WIRE MODE:
The four-wire mode provides continuous open-line communications
between the tender and up to five divers, or any combination of recom-
pression chambers or diving bells. The four-wire mode will give you
optimum performance and intelligibility by the MK2-DCI. Using this
method, everyone hears each other simultaneously. Therefore, the ear-
phones, speakers, and microphones must be isolated to prevent feed-
back. All earphones are connected in parallel. A four-wire cable is re-
quired for all stations. Two of the wires are used for the microphone
and two for the headset(s) and earphone(s) (see Figure 3). The diver
earphones should be connected to the “EARPHONE” binding post on
the surface unit (via the black banana plug located in the 1 or 2 Diver
sections). The banana plug on the tender’s OTS headset should be con-
nected to the “EARPHONE” banana plug (black; Tender section). The
remote plug on the headset should be connected to the “REM” recep-
tacle located in the Tender section. The tender’s microphone should be
connected to the red banana plug labeled “MICROPHONE” (Tender’s
section). The diver’s microphone should be connected to the “MICRO-
PHONE”banana plug(red)in the Diver’ssetionof theMK2-DCI.When
in the four-wire mode, everyone is on-line together. It is similar to a
telephone conference call.
Note
The “Diver Select” must be in the “BOTH” position for
four-wire communications in order to hear everyone. A
headset with a boom microphone has to be used by the
tender when using the MK2-DCI in the four-wire mode. If
you experience feedback from the headset’s microphone,
turn off the front panel speaker.
8

SECTION 6
BATTERIES:
The MK2-DCI Two-Diver Air Intercom can be powered by two 6-volt
heavy duty Alkaline batteries, rechargeable 6-volt batteries (RB-6), or
a 12-volt alternate source.
The following are options for the desired power source:
1) LANTERN BATTERIES: The MK2-DCI is designed to use two 6-
volt spring connector type batteries. To achieve optimum perfor-
mance, we recommend the use of 6-volt Alkaline batteries only!
Eveready or Duracell Alkaline batteries will provide the best results
for most diving operations. You can use standard 6-volt lantern bat-
teries with spring connectors as well. However, battery life will be
greatly reduced, and you will notice a substantial power drop when
transmitting.
INSTALLATION OF6-VOLTBATTERIES:Locate andloosenthe four
screws located on the front panel (see Figure 1, #19). These screws are
captive and will not come off the front panel. Remove front panel from
housing. Remove cotter pin from battery strap (see Figure 4, #3). Re-
move battery strap from battery housing (see Figure 4, #2). Insert both
6-volt, spring-type lantern batteries, springs facing toward battery PC
board (see Figure 4, #4). Verify that the batteries are secure on the bot-
tom of the housing and the backs are being held by the back plate. You
will notice the batteries can be installed with springs in any direction
on the PC board (see Figure 5). After batteries are installed, replace the
battery strap and cotter pin, dress the wires so they are not pinched
whenyou putthe frontpanelback inplace, replacethepanel, andtighten
the four screws (do not overtighten).
9

2) 6-VOLT RECHARGEABLE
BATTERY(RB-6V): Whenutiliz-
ingthe optionalRB-6Vsealed lead
acid battery, you will attain the
maximum performance of a self-
contained battery (two are re-
quired). Install the batteries as per
instructions found on page 9, “IN-
STALLATION OF6-VOLTBAT-
TERIES.”Torechargetheoptional
rechargeable batteries, you do not
need to remove them from the MK2-DCI. Just connect the RC-13
battery charger to the front panel 12-volt external power jack. Then
connect the charger’s power plug to any 110-volt, 60-cycle power
outlet and let the battery charge for no more than 14 hours.
10
Figure 5
Battery PC Board
Figure 4
Note: For operation outside the U.S., the optional RC-13I
charger should be used instead of the RC-13.

IMPORTANT SAFETY NOTE:
VERIFY BEFORE YOU CONNECT THE RC-13
BATTERY CHARGER TO THE EXTERNAL
POWER JACK THAT THE BATTERIES IN-
STALLED ARERECHARGEABLEBATTERIES.IT
IS RECOMMENDED THAT RECHARGEABLE
BATTERIES BE USED WHEN EXTERNAL
POWER IS SUPPLIED. THE EXTERNAL SOURCE
SHOULDPROVIDEAVOLTAGEGREATERTHAN
12 BUT LESS THAN 15 VOLTS. IT WILL RE-
CHARGE THE BATTERIES WHILE THE SYSTEM
IS OPERATING.
ALWAYSWAIT AMINIMUMOF20MINUTESFOR
ANY GASSES EXPELLED DURING CHARGING
TO DISSIPATE BEFORE POWERING UP THE
MK2-DCI. AVOID SMOKING, OPEN FLAMES, OR
STRIKING A MATCH WHILE CHARGING BAT-
TERIES.
3) ALTERNATE POWER SOURCE: The external receptacle (see Fig-
ure 1, #5) provides an easy terminal for a marine or automotive 12-volt
DC source. The power source should provide 12 volts and a minimum
of 3 amps capacity. The alternate power source connection is also used
for charging the battery.
4) LOW BATTERY LEDs: The four LEDs illuminate one at a time,
starting with the upper LED. Green represents fresh or fully charged
batteries. As long as the power is 11 volts or higher, the top green LED
will illuminate. As the power decreases to approximately 10 volts, the
second green LED will illuminate. The top green LED shuts off. When
power falls to approximately 9 volts, the yellow LED will illuminate
and the green LED will shut down. When power reaches approximately
8volts, the redLED willilluminate andthe yellowLED willshut down.
11

At this point the MK2-DCI will audibly start warning you of lower
power with a beeping sound every 30 seconds. When the voltage falls
to about 7 volts, the red LED will start blinking and the warning beeps
will come every 30 seconds. When the voltage falls below 7 volts, the
beep occurs every 15 seconds. Below 6 volts the LED blinks quickly
for a few seconds, after which the unit shuts off to save the battery from
damage. The warning mode continues until the user installs fresh bat-
teries, charges the batteries, or connects a 12-volt power source, or un-
til the power drops enough to shut down the MK2-DCI (see chart be-
low).
COLOR VOLTAGE ON BEEPING
Green 11 volts DC or above Solid None
Green Approximately 10 volts Solid None
Yellow Approximately 9 volts Solid None
Red Approximately 8 volts Solid Every 30 seconds
Approximately 7 volts Blinking Every 30 seconds
Below 7 volts Blinking Every 15 seconds
12
LED CHART

SECTION 7
HELPFUL HINTS:
1) Before diving operations begin, check to be sure the microphone,
earphones, and wire connections are secure and operating properly.
Ninety percent of all problems in communications turn out to be a
problem with one of the above.
2) When in the four-wire mode, you must use a headset with a boom
microphone, and the Diver Select switch must be in the “BOTH”
position. If feedback is present, switch off the front panel speaker
(see Figure 1, #24).
3)Avoidexcessivetender-to-diver volume.Most ofthetime, whenthere
is too much volume, the diver will hear distortion and ask for more
volume!
4) Before diving operations, always check the battery power level, and
replace or recharge the batteries if necessary.
5) Make certain the headphone and remote PTT plugs are securely in-
serted into the proper receptacle.
6) When in the four-wire mode and a wire breaks, try setting the system
up in the two-wire communication mode (see Figure 2), and con-
tinue diving operations.
7) Secure the MK2-DCI if using the unit on a vessel that is rolling
about. Also strain-relief the umbilical(s) so they will not pull on the
MK2-DCI.
8) Ensure the umbilicals are dressed out so as not to trip anyone.
13

14
TROUBLESHOOTING FOR MK2-DCI
PROBLEM PROBABLE CAUSE REMEDY
No Power Battery exhausted Replace battery
Battery leads loose Check battery
connectors
Defective ON/OFF Change switch
switch
Board connector not Clean pins
making contact
Open circuit on board Repair or replace board
Power only for a short Defective boot circuit Repair or replace
time when power switch board
is turned on
Defective CPU chip Replace CPU or
replace board
No diver voice Loose connection at Check connector;
ribbon lead connector clean or reconnect
Board connectors Clean pins and
loose reconnect
Defective PCB Replace board
Defective speaker Replace switch
ON/OFF switch
Defective volume Replace control
controls
Defective panel Replace speaker
speaker
Defective pre-amp Replace
chip
Defective relay Replace
PTT logic circuits Repair or replace
defective board
No tender voice Defective board Replace
Defective relay Replace

PROBLEM PROBABLE CAUSE REMEDY
Defective pre-amp Replace
chip
Open trace on board Repair trace or
replace board
PTT logic circuits Repair or replace
defective board
Weak battery Charge (if
rechargeable) or replace
Microphone pre-amp Trace signal to find
circuit defective fault and replace
defective part
No record-out function Board connector not Clean pins or replace
making contact defective connector
Defective record amp Trace fault around
record op-amp and
replace faulty part
Replace board
Weak output to divers Power amplifier Replace power
and tender defective amplifier chip
Defective component Trace part and replace
that supports the power
amplifier is defective
Distorted unintelligible Bias supply faulty Check supply and
speech replace defective part
Cannot cross-talk Defective cross-talk Replace cross-talk
divers switch switch
Defective relays Replace relays
CPU defective Replace CPU
Tender-to-diver faulty Defective PTT switch Replace PTT switch
in two-wire mode
Defective relays Replace relays
Defective CPU Replace CPU
15

16
Undersea Systems International
dba
Ocean Technology Systems
LIMITED WARRANTY
The MK2-DCI is fully warrantied against defects in materi-
als and workmanship for a period of 1 year from the time of
purchase. Our obligation under this warranty is limited to
the replacing of any part or parts that prove to our satisfac-
tion to have been defective and that have not been misused
or carelessly handled. Labor is warrantied for 1 year from
time of purchase. The complete unit and/or part must be re-
turned to our factory, transportation charges prepaid. We
reserve the right to decline responsibility where repairs have
been made or attempted by other than an Ocean Technology
Systems factory-trained service center or properly trained
personnel. In no event shall Ocean Technology Systems be
liable for consequential damages.
3133 West Harvard Street, Santa Ana, CA 92704, USA
Telephone [phone], Toll-Free [phone], Fax [phone]
www.oceantechnologysystems.com
© Copyright 2001 Ocean Technology Systems

NOTES: