Amron 2820A-4003 User manual

Instruction Manual
For
Amron International Diving Supply, Inc.
Model 2820A-4003 & 2820A-4003E
Chamber Communicator
S/N
This manual and the information contained herein is provided for use as an operation and
maintenance guide. No license or rights to manufacture, reproduce, or sell either the manual or
articles described herein are given. Amron International Diving Supply, Inc. reserves the right to
change specifications without notice.
Amron International Diving Supply, Inc.
1380 Aspen Way
Vista, California 92081 U.S.A
Phone:[phone]
Fax [phone]
Email: [email protected]
Website: www.amronintl.com
Copyright © 2009, Amron International, Inc.
Revised August 2010

TABLE OF CONTENTS
CONTENTS SECTION
Specifications 1
General Information 2
Description....................................................................................................................2.1
Description 2820A-4003E.............................................................................................2.2
Drawing, Front Panel Controls Model 2820A-4003.......................................................2.3
Drawing, Front Panel Controls Model 2820A-4003E....................................................2.4
Options 3
Warranty and Service Policy 4
Limited Warranty...........................................................................................................4.1
Service Policy................................................................................................................4.2
Controls and Connections 5
General .........................................................................................................................5.1
Operator Controls..........................................................................................................5.2
Operator Connections...................................................................................................5.3
Drawing, Operator Connections - P.T.T. Microphone...................................................5.4
Drawing, Operator Connections - Headset...................................................................5.5
Drawing, Chamber Connections...................................................................................5.6
Installation & Operation 6
Installation.....................................................................................................................6.1
Push to Talk Microphone Connections .........................................................................6.2
Headset Connections....................................................................................................6.3
Initial Set Up..................................................................................................................6.4
Headset Operation........................................................................................................6.5
Description of Operator Controls...................................................................................6.6
Theory of Operation 7
Amplifier Card 2832-202...............................................................................................7.1
Battery Charger Card, 2324-202...................................................................................7.2
Entertainment Amplifier Circuit......................................................................................7.3
Functional Block Diagram - Model 2820A-4003............................................................7.4
I

TABLE OF CONTENTS
II
Maintenance 8
General .........................................................................................................................8.1
Trouble Shooting...........................................................................................................8.2
Problems and their Possible Causes............................................................................8.3
Adjustments ..................................................................................................................8.4
Drawings 9
General .........................................................................................................................9.1
Schematic 2820A-4003.................................................................................................9.2
Schematic 2820A-4003E ..............................................................................................9.3
Parts Identifier 2832-202...............................................................................................9.4
Parts Identifier 2324-202...............................................................................................9.5
Parts Identifier - Front Panel 2820A-4003.....................................................................9.6
Parts Identifier - Front Panel 2820A-4003E..................................................................9.7
Parts Identifier - Rear Chassis 2820A-4003 & 2820A-4003E.......................................9.8
Mounting Detail 2820A-4003 & 2820A-4003E............................................................. 9.9
Parts List 10
General .......................................................................................................................10.1
Model 2820A-4003 Chamber Communicator..............................................................10.2
Model 2820A-4003E Chamber Communicator w/ Entertainment...............................10.3
2820A-4003-400M Front Panel Assembly..................................................................10.4
2820A-4003E-400M Front Panel Assembly, Entertainment .......................................10.5
2820A-4003-500C Chassis Assembly ........................................................................10.6
2820A-4003-FS Field Spares Kit, Model 2820A-4003............................................... 10.7
Optional Spares ..........................................................................................................10.8

SPECIFICATIONS
SPECIFICATIONS 1.1
Electrical
Input Impedance (each Input)...........................................................................250 Ohms
Frequency Response................................................................................300 - 10000 Hz
Common Mode Rejection..........................................................................40 dB Minimum
Current Drain
Maximum Full Volume...............................................................................................3 ADC
Minimum Quiescent ...........................................................................................0.250 ADC
Output Impedance...................................................................................................4 Ohm
DC Power Requirements Voltage...........................................................12 VDC Nominal
(For Operation on External) - Range..............................9 Volts Min. - 18 Volts Maximum
Battery Current............................................................................................ 3 Amps Peak
Sensitivity (input)...............................................................................................16 mVRMS
Output Power (Peak @ 4 Ohm Load, 12 Vdc)..........................................20 Watts Audio
Battery Backup Life.............................................................................................20 Hours
Operating Voltage.................................................................. 115/230 Volts AC 50/60 Hz
Electrical Model 2820-4003E, Entertainment Option
Output Power........................................................................................................ 6 Watts
Sensitivity (input)...................................................................................................... 1 Volt
Mechanical
Panel..........................................................................................................Stainless Steel
Enclosure.................................................................................Black Anodized Aluminum
Dimensions
Length................................................................................................10.125 in. (25.7 cm)
Depth.......................................................................................................7.5 in. (19.1 cm)
Height......................................................................................................7.5 in. (19.1 cm)
Weight With Batteries.................................................................................15 lbs. (6.8 kg)
1

GENERAL INFORMATION
DESCRIPTION 2.1
The AMRON INTERNATIONAL Inc., AMCOM II Model 2820A-4003 and 2820A-4003E are
decompression chamber communication systems, providing two-way communications between
the chamber operator and the occupants of the chamber. The Model 2820A-4003 & 2820A-4003E
are used in conjunction with a chamber talk back speaker i.e., the Amron Model 3113, 3114, 3115,
3125 or 3126. The Model 2820A-4003E is exactly the same as the 2820A-4003, but also includes
a separate entertainment channel, amplifier. This is used with the Model 3130 entertainment
speaker to provide music (audio) to the chamber occupants. All references to the Model 2820A-
4003 apply as well to the 2820A-4003E.
The AMCOM II chamber communication systems are full feature hard wire, two lock communicator
systems. The AMCOM II has independent volume controls (operator, inner lock, & outer lock.), as
well as separate on/off controls for each lock. Both models are supplied with hand-held
microphones, for use by the operator.
The 2820A-4003 has the capability of two modes of operation, a simple intercom type operation,
or telephone type operation using headsets both inside and outside the chamber. The two modes
are known as, 2-wire and/or full duplex (4-wire) communications.
The two-wire mode of operation is a simplex type system. The operator monitors the chamber
conversations via a talkback speaker mounted on the front panel of the unit. The operator can talk
to the occupants by using the hand held microphone, or by using the Push-To-Talk (PTT) switch
and speaking into the front panel talk back speaker. Inside the chamber is a talk back speaker,
which picks up the sounds within the chamber. When the operator speaks to the chamber, the
2820A-4003 connects the chamber internal speaker to the amplifier output and the operator voice
is broadcast to the chamber occupants. All switching operations take place outside the chamber.
The full duplex mode of operation requires the use of two headsets, one for the operator and one
for use inside the chamber. Conversations are full duplex, and occur as with a telephone, and do
not require the use of the PTT switch. Additional headsets can be used both inside and outside the
chamber, allowing several parties to communicate. The system also permits mixed operation,
however any mixed operation does require the use of the PTT switch. The PTT switch also
provides an over-ride function, operator conversation over-rides occupant. Full duplex is a
communications system designed from the “ground-up” to take advantage of the current “state of
the art” in semiconductor technology and provide superior communications.
The unit operates from 115/230 VAC 50/60 Hz and has internal rechargeable battery back-up. It
also can be operated from an external 12 VDC power source.
2

GENERAL INFORMATION
DESCRIPTION, 2820A-4003E 2.2
The model 2820A-4003E has a separate amplifier to provide entertainment audio for use in the
chamber. The entertainment audio output is connected to a separate speaker within the chamber,
i.e., the Amron model 3130. Stereo input connections (RCA jacks) are provided on the back panel
for connection to the desired audio entertainment source. The audio source can be audio (music)
from any source i.e., AM, FM, tape recorder, CD player, TV or other source as desired.
The 2820A-4003E has a separate ON/OFF, volume control for the entertainment channel, also the
entertainment audio is interrupted whenever the hand held microphone or the push-to-talk switch
is used. This automatically cuts off entertainment audio to the chamber entertainment speaker
when voice communications are in process, (operator to chamber, PTT).
3

GENERAL INFORMATION
FRONT PANEL CONTROLS MODEL 2820A-4003 2.3
4

GENERAL INFORMATION
FRONT PANEL CONTROLS MODEL 2820A-4003E 2.4
5

OPTIONS
OPTIONS 3.1
Model 2821-28 Remote Push-To-Talk (2-Wire Operation)
AMRON headset extension with push-to-talk belt module, jacks for headset, and 25 cable. (Use
with Model 2460-28 or Model 2401-28 headset).
Model 2822-28 Remote Walk-and-Talk (4-Wire Operation)
Amron full duplex (4-wire) headset extension, belt module with 25 feet cable. (Use with Model
2460-28 headset)
Model 2460-28 Headset
Headset with boom microphone and color coded dual banana plugs to mate color coded inputs on
Amron communicators and accessory items.
Model 2460SM-28
Single earphone with same functions as 2460-28.
Model 3113 Chamber Comm. Box
Decompression chamber communication box. Folded acoustic horn talk-back speaker, 15 watt,
headset jack, MS input connector.
Model 3114 Chamber Comm. Box
Decompression chamber communication box. Three inch talk-back speaker, mylar impregnated
cloth cone, three foot SJO cord.
Model 3115 Chamber Comm Box
Decompression chamber communication box. Same as Model 3113, also has a speaker ON/OFF
switch.
Model 3125 Chamber Combo Box
Decompression chamber combination communication/junction box, designed for inner lock
functions. Mounts direct to chamber penetrator (eliminating chamber wiring), includes; penetrator
adapter bushing, chamber talk-back speaker, speaker ON/OFF switch, headset jack, temperature
probe, sound powered phone & bracket, and power connection circuit for chamber internal
conditioning system & chamber scrubber.
Model 3126 Chamber Combo Box
Decompression chamber combination communication box, outer-lock design. Mounts direct to
chamber penetrator (eliminating chamber wiring), includes penetrator adapter bushing, chamber
talk-back speaker, speaker ON/OFF switch, headset jack, sound powered phone & bracket.
Model 3127 Chamber Junction Box
Outside junction box, for use with the Model 3125 & 3126. Includes 12 pin electrical penetrator,
mounting adapter, and MS connector to mate with Model 3128 wiring harness.
6

OPTIONS
7
OPTIONS (Continued) 3.1
Model 3128 Chamber Wiring Harness (Custom)
Decompression chamber wiring harness, one end connects directly to 2820-4003, other end
connects to model 3127 junction box. Pre wired, tested and customized to your chamber size
requirements.
Model 3130 Chamber Entertainment Speaker
Decompression chamber entertainment speaker. Speaker is 15 watt, 8 inch, music quality, mylar
impregnated cloth cone. Includes 6 each headset jacks, for mini phone plugs.
Model 2460-31R Headset
Headset with boom microphone, for use in decompression chambers, has 4 pin connector to plug
directly into chamber comm boxes.
Model 2460-31R-25 Headset Extension
Integrated headset extension for Model 2460-31R headset when used with chamber
communications boxes. Flexible 25 foot cord, with 4 pin audio connector.

WARRANTY
LIMITED WARRANTY 4.1
AMRON INTERNATIONAL DIVING SUPPLY, INC. warrants that it’s products are free from
defects in material and workmanship under normal use and service, as described in AMRON
INTERNATIONAL DIVING SUPPLY, Inc.. Literature covering this product, for a period of 90 days
from date of shipment. Amron’s obligation under this warranty is limited to the repair of or
replacement, at AMRON’S option, of defective material. This warranty shall not cover defects
which are the result of misuse, negligence, accident, repair or alterations.
SERVICE POLICY 4.2
AMRON INTERNATIONAL encourages owners of equipment to call [phone] for assistance
if problems are encountered. Every effort will be made to assist in solving your problem.
Equipment which must be returned to the factory for repairs should be safely packaged, insured,
and shipped prepaid to: Amron International, Inc.
1380 Aspen way
Vista, CA 92081
Be sure to include the following information:
Your Name
Your Company
Shipping Address
Phone Number
Contact Name
A short description of the problem is most helpful.
Valid in warranty repairs will be made at no charge. Out of warranty repairs will be handled in the
same fashion, except you will be advised of the repair charges before any work is done.
8

CONTROLS & CONNECTIONS
GENERAL 5.1
Before using the AMCOM II chamber communications system, you should familiarize yourself with
its operating controls and connections. Improper use of controls and connections may deprive the
user of the full benefit of this communication system. Reference: Figure 1 & 2 Front Panel model
2820A-4003 and 2820A-4003E.
OPERATOR CONTROLS 5.2
Power Switch
Turns unit on/off, applies power to the unit from internal rechargeable batteries or from external
source.
Speaker Switch
Turns Speaker ON/OFF.
PANEL MICROHPONE
Condenser microphone to pickup tender voice, it operates when Speaker Switch is ON and PTT
Switch is depressed.
P.T.T. Switch
Push to Talk Switch enables operator to speak to the occupants of the chamber, used in the 2-
wire mode. Push to talk is not required when operating in full duplex (4-wire) mode. In the full
duplex mode this switch allows the operator to interrupt all locks with a priority message.
Volume Controls
Controls the volume for the operator, adjusts the volume level of the audio originating in the inner
and outer locks.
OPERATOR CONNECTIONS 5.3
Tape Recorder (output)
Is an RCA jack connection for tape recording conversations, output is approx 300 mVRMS.
Microphone (input)
Microphone input is a dual banana jack connection for the headset microphone. Jacks are color
coded red.
Headset (input/output)
Headset is a dual banana jack connection for headset earphones, external remote speaker, or
hand held push to talk microphone. In 2-wire mode of operation both headset microphone and
earphones are plugged into this jack, conversation (up-link & down-link) are switched
automatically when push to talk switch is actuated. In the full duplex mode this jack is listen only,
both sides of the conversations are heard (to and from the chamber). Jacks are color coded black.
9

CONTROLS & CONNECTIONS
OPERATOR CONNECTIONS (Continued) 5.3
P.T.T. (input)
Push To Talk (input) Is a dual banana jack connection for remote keying of push to talk single
contact closure, close to talk to the chamber, open to listen to the chamber. Banana jacks are
color coded yellow.
Battery Condition
Indicator tells whether the unit is on or off and provides information regarding the condition
of the backup battery power. If the unit is being operated from AC power the light will be on
steady. If the unit is operating from the internal batteries (AC power is off or if the unit is not
plugged in), the indicator will display the condition of the battery charge, as follows;
1. A steady green light indicates batteries are of sufficient voltage to operate the unit.
2. Blinking green light indicates batteries are approaching a low level, approximately 3 hour
operating time left, from the time the light began to blink.
3. A steady red light indicates battery voltage below reliable operating level. First function to
fail will be communications to the chamber, (PTT) in the 2-wire mode of operation
Note: Unit must be on for 5 minutes before display can be considered accurate. Batteries tend to
recover when turned off, this condition is known as surface charge. Due to the surface charge the
voltage will be high when first turned on and will drop rather quickly to its actual level.
Lock Controls
1. Volume - Inner Lock Controls volume level of operator’s voice as heard by the inner
lock. In the full duplex mode of operation it sets the lock’s side-tone volume
(headset).
2. Volume - Outer Lock, Controls volume level of operator’s voice as heard by the
inner lock. In the full duplex mode of operation it sets the lock’s side tone volume
(headset).
3. On/Off- Inner Lock - Disconnects inner lock, disables all communication with the
inner lock.
4. On/Off - Outer lock - Disconnects outer lock, disables all communication with the
outer lock.
10

CONTROLS & CONNECTIONS
OPERATOR CONNECTIONS (Continued) 5.3
Entertainment Controls, Model 2820A-4003E Only
Volume - Adjusts the volume level of the entertainment audio within the chamber and is located
with the inner lock group of controls.
Rear Panel Connections
MS Connector - Electrical connections to chamber, inner and outer lock audio signals,
entertainment channel output (2820A-4003E only) and power connections for operation from a 12
VDC source.
Entertainment input jacks - Model 2820A-4003E only, two each RCA type jacks for audio input
(two jacks are provided for stereo input, signal is mixed internally for a monaural output).
AC Inlet Jack – Standard jack for AC power cord, supplied with units.
11

CONTROLS & CONNECTIONS
2820A-4003 PUSH TO TALK MICROPHONE 5.4
12

CONTROLS & CONNECTIONS
2820A-4003 HEADSET CONNECTION 5.5
13

CONTROLS & CONNECTIONS
SCHEMATIC CONNECTION MODEL 2820A-4003 TO CHAMBER 5.6
14

INSTALLATION & OPERATION
INSTALLATION 6.1
Chamber communication wiring - see examples outlined on schematic 2820A-4003 and the 3128
if purchased. Connect the lock speakers to the cabling harness. The lock speaker is normally
wired to the microphone lines (J1 Pins A & B or E & F)
Turn power off, AC power unplugged, connect chamber wiring cable connector to J-1.
Plug 2820A-4003 into AC power source, 100/240 VAC 50/60 Hz.
Connect audio source to RCA jacks (model 2820A-4003E only), if stereo connect left channel to
one jack and right channel to other jack, if monaural source connect to either jack.
Unit is now ready for test, functionally test unit as described, par 6.4.
Install unit into panel cutout, and fasten with four brass thumbscrews provided.
PUSH TO TALK MICROPHONE CONNECTIONS 6.2
The push to talk microphone has two dual banana plugs. Insert the yellow banana plug into the
yellow jacks, (push to talk jacks on front of 2820A-4003). Insert the black dual banana plug into
the black jacks, (jacks labeled headset on the front of the 2820A-4003). A microphone holder is
provided on the front panel to facilitate storage of the microphone when not being used.
HEADSET CONNECTIONS 6.3
Connect headset by inserting the red and black banana plugs into the red and black jacks on the
front of the 2820A-4003 panels, note headset is an optional item.
15

INSTALLATION & OPERATION
INITIAL SET UP 6.4
Check to see that the inner lock, outer lock, and speaker switch are all on. Set volume controls to
low. Confirm that AC power is available; AC power LED indicator should be on. Turn power ON.
Check to see that battery condition indicator LED is on.
Have someone in the inner lock talk, and adjust operator volume control to a comfortable listening
level.
Operator should then give a short count, use hand held microphone. Operation of the unit with the
microphone is simple and straightforward. Hold the microphone about 1 inch away from mouth,
depress the push to talk lever on the side of the microphone and speak clearly and directly into the
microphone. Release the push to talk lever when finished. Someone in the inner lock should
determine what is a comfortable listening level having the operator adjust as needed, (adjust the
inner lock volume control).
Adjustment of volume controls, volume levels should be sufficient to ensure good communications.
If excessive feedback occurs see SECTION 8.2 for instructions on adjusting the operator volume
level to the chamber. This adjustment should be made to optimize the volume levels during initial
installation.
Confirm that the inner lock on/off switch works properly. When off, all communication to and from
inner lock stops.
HEADSET OPERATION 6.5
Test headset operation (if desired). Note with operator and inner lock on headset, you do not need
to use the push to talk switch.
Depressing the push to talk switch when using headsets, cuts off the locks allowing the operator to
have priority. This feature provides the operator the ability to interrupt a conversation and convey
an important message.
When communicating with a headset inside the chamber it is not necessary to use the push to talk
switch. All headsets (i. e. Operator, inner lock, outer lock) can talk to each other without using the
push to talk function. This permits a three party conversation similar to that of a telephone. You
may find it necessary to turn off the 2820A-4003 speaker while the operator is using a headset. A
feedback condition can occur while using a headset (headset microphone is receiving the sound
from the speaker causing the feedback) it will depend upon two factors, the volume level and the
distance between the headset and the speaker.
Repeat the above procedures for the outer lock.
16

INSTALLATION & OPERATION
17
DESCRIPTION OF OPERATOR CONTROLS 6.6
Power On - Off - this switch controls power to the unit. This switch does not disable the battery
charging circuit. The battery condition indicator should come on when this switch is in the ON
position.
Speaker On - Off - this switch turns the loudspeaker on the unit off. It would normally be off when
using a headset to eliminate feedback. The yellow jacks allow remote operation.
Push to talk - this momentary switch is pressed to speak to the chamber.
Volume - the control for the operator determines loudness of communication from chamber. The
controls for the inner and outer lock determine the volume level in the chamber.
Battery Condition (indicator) - displays visual indication of battery condition. On - steady light when
unit is on indicates battery is in good charge state. Blink - blinking light indicates battery level is
approaching a low level, approximately 3 hours of operating time left. Off - light is out when unit is
on means the battery voltage is below that required for reliable operation. The first function to fail
because of low voltage is down link communication in two-wire operation, (operator can hear locks
but locks can’t hear operator).
Tape recorder - output signal for driving external recorder.
Output level is factory set for 300 mVRMS. Normally the volume levels should be well matched
between locks and operator. If there is a great difference an investigation should be made into the
possible cause. This might be an indication of deteriorating cable, electrical connections, lock
speaker, or headset.
Microphone - (input) jack for attaching microphone from operator headset.
Headset - (input/output) jack for attaching headset earphones.