Undersea Systems International, Inc.
dba
Ocean Technology Systems
WT-MK2 Wireless Tender
The WT-MK2 Wireless Tender is designed to operate with any hard-wire communication system that will function in
the four-wire mode and that has front-panel banana-type connectors. It comes in two parts: 1) an electronics module
(WT-MK2) designed to interface with the diver communication intercom, and 2) a remote transceiver and headset
with boom microphone (the Tender Unit).
The WT-MK2 is a radio transceiver that, when connected to a four-wire hard-wire communication intercom, will
provide full duplex communications between the
tender and the diver(s). The manufacturer of the fullduplex radios claims a maximum range of 1/4 mile.
However, we have found that environmental (e.g.,
weather) conditions dramatically affect the range.
We estimate a nominal range of between 75 yards
and 1/4 mile.
With fresh batteries, the WT-MK2 and Tender Unit
will operate for approximately 5 hours. For complete
specifications, refer to the user manual supplied by
the manufacturer of the full-duplex radios.
Legend for Figure 1
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8)
Figure 1
Cover for the WT-MK2
(1) of (4) screws holding top cover
On/Off switch (powers unit on/off)
LED (indicates when power is on or unit is charging)
Charge input jacks
Cable with earphone and microphone banana-style connectors
Red banana connector. This is connected to the microphone jack located on the hard-wire intercom.
Black banana connector. This is connected to the earphone jack located on the hard-wire intercom.
Operating Instructions
TWT-MK2: Connect the red banana plug (Figure 1, #7) to the microphone banana jack for the tender or one of the
divers, located on the hard-wire intercom. Connect the black banana plug (Figure 1, #8) to the earphone banana jack
for the tender or one of the divers, located on the hard-wire intercom. Power for the WT-MK2 is controlled by the
external ON/OFF switch (Figure 1, #3). When power is on and the batteries are sufficiently charged, the red LED
(Figure 1, #4) will be on. Volume and channel are factory-preset. Volume is controlled with the hard-wire communication system.
Tender Unit: Refer to Figure 2. Turn the Tender Unit volume control clockwise to turn the unit on. The "TALK"
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button should be pressed down and the "CHANNEL" button should be up; verify that the LED indicator labeled "A"
is on and yellow in color to assure that these settings are correct. The "B" indicator should be off. Plug the headset
into the "mic/earphone" jack on the side of the unit. Adjust the earphone volume to a comfortable level. Adjust the
headset boom microphone to within 1/4" from your lips.
Everyone should talk at a moderate level.
Figure 2: Tender Unit
Charging
When the "BATT" indicator light on the Tender Unit turns on, the battery charge is low. Promptly charge the batteries of both the Tender Unit and the WT-MK2. Only charge the batteries when their charge is low. When charging
NiCad batteries, allow them to charge fully before use. Refer to Figure 3 for illustrations of the chargers for the
WT-MK2 and Tender Unit.
WT-MK2: The "ON/OFF" switch must be in OFF position for charging. Insert the double mini banana plug from the WTMK2 charger into the jacks (Figure 1, #5) on the side of the unit. The LED (Figure 1, #4) will illuminate to indicate charging.
Tender Unit: The volume control must be fully counterclockwise. Insert the plug from the Tender charger into the
"CHARGE" jack on the side of the Tender unit. Battery LED will illuminate to indicate charging.
Both units reach full charge in 12–14 hours. Do not charge for more than 24 hours.
If the batteries no longer hold a charge, they will need to be replaced. See the "Battery Replacement" section.
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Battery Replacement
The supplied NiCad batteries are expected to last 250–300 charge cycles under normal usage. When the batteries no
longer hold a charge, they will need to be replaced with a 4-pack of AA NiCad batteries according to the following
instructions.
WT-MK2:
WT-MK2 battery replacement should be done by qualified service personnel. Refer to Figure 4 throughout.
1) Remove the four cover screws and set the cover (#1) aside.
2) Remove the four screws (#2) that hold the circuit board.
3) Remove the nut from the external power switch (#3) , and push the power switch into the case.
4) Pull the external LED indicator (#4) into the case.
5) Lift the internal full-duplex radio ("Master" radio) (#5) with the circuit board out of the case, flip it over, and set
it aside. It will still be connected to the case by the wiring.
6) Remove the flathead screw (#6) that secures the Master radio to the circuit board.
7) Remove the plug (#7) from the "mic/earphone" jack.
8) Free the radio from the board (#8), but be careful not to damage the wiring that maintains its connection to the
board.
9) Slide off the rear cover (#9), remove the battery, and disconnect the harness. Connect the new battery to the harness and place the battery into the unit. Replace the rear cover.
10) To reassemble the WT-MK2, follow steps 1 through 8 in reverse.
11) Fully charge the new batteries before use (see the "Charging" section).
Tender Unit:
Slide off the rear cover, remove the battery, and disconnect the harness. Connect the new battery to the harness and
place the battery into the unit. Replace the rear cover.
Tender Unit
Charger
WT-MK2
Charger
Figure 4
Figure 3
Refer to the Library page of our Web site, www.otscomm.com, for a list of
any changes made to this manual since its publication.
Undersea Systems International, Inc., dba Ocean Technology Systems
3133 West Harvard Street • Santa Ana • California • 92704 • Toll-Free (800) 550-1984 • Tel (714) 754-7848 • Fax (714) 966-1639
Email: ots@otscomm.com • Web: www.otscomm.com
Specifications are subject to change without prior notice.
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506056-000 Rev.D