DTC Communications PD2TX100S COFDM Video Transmitter User Manual OP1920492Palladium2txRev003
DTC Communications Inc. COFDM Video Transmitter OP1920492Palladium2txRev003
Manual
COFDM Transmitter
Model Pd2-TX-100 100 mW Output
Palladium II Digital
TELEMETRY
CHANNEL
Palladium II
VIDEO TX
COMMUNICATIONS
DTC COMMUNICATIONS, INC.
2
warranty
DTC warrants its manufactured components
against defects in material and workmanship
for a period of two (2) years, commencing on
the date of original purchase.
Products manufactured by others that are
approved for use with DTC equipment are
warranted for the manufacturer’s warranty
period, commencing from the date of shipment
from DTC.
PN OP1920492 REV 0.003
copyright notice
Copyright © 2005 - 2008
DTC Communications, Inc. All rights
reserved. No part of this document may be
reproduced, transmitted, transcribed, stored
in a retrieval system or translated into any
language or computer language, in any form
or by any means, including but not limited to
electronic, magnetic, mechanical, optical,
chemical, manual or otherwise, without the
prior written permission of DTC
Communications, Inc.
disclaimer
The information in the document is subject to
change without notice. DTC makes no
representations or warranties with respect to
the contents hereof, and specifically disclaims
any implied warranties of merchantability or
fitness for a particular purpose. DTC reserves
the right to revise this publication and to
make changes from time to time in the
content hereof without obligation of DTC to
notify any person of such revision or changes.
trademarks
Trademarks of DTC Communications, Inc.
include:
• DTC
• MiniPIXTM
• SplitPIXTM
• DynaViewTM
• PalladiumTM
• ArmorNetTM
Other product names used in this manual are
the properties of their respective owners.
how to contact DTC
For operator and troubleshooting information,
customers are encouraged to refer to the
details in this manual. For additional
clarification or instruction, or to order parts,
contact DTC.
Customer Service is available Monday through
Friday between the hours of 9:00 AM and
5:00 PM EST at:
Tel: 603-880-4411
Fax: 603-880-6965
Website: www.dtccom.com
Email: info@dtccom.com
486 Amherst Street
Nashua, New Hampshire 03063
DTC COMMUNICATIONS, INC. 3
NOTE: Describes special issues you should
be aware of while using a particular function.
WARNING: Calls out situations in which
equipment could be damaged or a process
could be incorrectly implemented, but in
which operator safety is not a factor.
TIP: Describes application hints.
RF EXPOSURE STATEMENT
NOTE: Unless specificaly designed for body-
worn applications, the antenna must be kept
at least 20 cm away from the body of the
user.
NOTE: Do not allow the device to directly
contact the skin due to warm operating
temperatures.
manual conventions
Quick Start ............................................................................ 4-5
Accessories ............................................................................... 5
Introduction ............................................................................... 6
Operation ............................................................................... 7
Using your Palladium II Transmitter ............................................. 7
Changing your Transmitter Configuration .................................... 7
Components ........................................................................... 8-9
Programming ...................................................................... 10-17
System PC Controller Application Software .............................. 10
Transmitter Control Application ................................................. 11
Specifications ..................................................................... 18-19
Notes ........................................................................ 20-21
Warranty ............................................................................. 22
Contact Us ............................................................................. 23
TABLE OF CONTENTS
DTC COMMUNICATIONS, INC.
4
TELEMETRY
CHANNEL
Palladium II
VIDEO TX
Antenna
Audio
Camera
Battery Pack
Power Option
1Connect the transmitter antenna to the SMA connector on the bottom of
the Palladium unit.
2If you plan to use audio, connect one or two microphones to the Audio 1
and/or Audio 2 LEMO connectors. If using monaural, use Audio 1.
3Connect power and video input via the Multi I/O cable to the 6-pin
Hirose connector:
a Attach your camera video input (75 ohm composite video source in
PAL or NTSC) to the Multi I/O cable BNC connector.
b Apply the necessary power to your camera (use supplied cable or
external source) and turn ON.
c Attach a 12 VDC power source (such as the supplied battery pack or
the AC power adapter) to the Multi I/O cable via the Molex connector.
The input voltage range is from 10 to 16 VDC.
WARNING: Do not apply power to the transmitter unless an antenna
or non-radiating load is connected to the Antenna SMA connector.
Complete these steps:
1
2
3
Palladium Transmitter, Top View
QUICK START
Typical Wiring Configuration
A2
L
A1
R/M
DTC COMMUNICATIONS, INC. 5
TELEMETRY
CHANNEL
Palladium II
VIDEO TX
4Set to the required configuration as indicated by the channel numbers.
Refer to the Programming section on page 10 for more information on
channel settings. Your Transmitter is now operational. Confirm its
signal with your Palladium Receiver.
4
QUICK START
Palladium Pd2-TX-100 Transmitter,
Front View
Antenna Connector
Accessories
• 10 cell AA Battery Pack
• 12 VDC 2.5A Power Supply & AC Line Cord
• Microphone, Body-Worn, (2)
• Power & Video Cable
• Camera Power Cable (2.1 mm plug)
• DC Power Cable, flying lead
• Camera Power Cable, flying lead
• Programming Cable
• Antenna, ANT2A
• VidiWire on-body antenna system, VW-ANT
• Palladium II Configuration Software
• 16-Pin Data Chaining & Control Connector Cable
• Transport Case
DTC COMMUNICATIONS, INC.
6
INTRODUCTION
Palladium II
The Palladium II Series of digital video transmitters provide exceptional
video quality in high multipath environments. They are ideal for use inside
buildings, in urban areas, and in other applications where multipath
would normally cause video tearing or breakup.
All Palladium II Series transmitters offer three bandwidth modes: DVB-T
(6, 7, 8 MHz), Narrow (2.5 MHz), and Ultra Narrow (1.25 MHz) channel
spacing. DVB-T utilizes 2000 carriers to transmit video and two channels
of voice and data. Palladium II transmitters may be located on adjacent
channels without a guard band. AES 128-bit encryption ensures users of
secure communications.
The Palladium 100 is a small transmitter with a 100 mW RF power output.
This unit is ideal for concealments and shorter range robotic and UAV
applications. The package is only 4.2” x 2.6” x 0.65” (approximate
dimensions not including connectors). Power consumption is 7.5 Watts.
Operation time on a fresh set of Lithium batteries is approximately three
hours. All connections are conveniently located off the ends of the unit.
Many users will want to power this device with disposable batteries.
Palladium Pd2-TX-100
100-Milliwatt Digital Transmitter NOTE: Use only Lithium batteries with this device.
TELEMETRY
CHANNEL
Palladium II
VIDEO TX
DTC COMMUNICATIONS, INC. 7
OPERATION
Using your Palladium II Transmitter
Follow the instructions given in the Quick Start section on pages 4-5.
When power is first applied to the Palladium, the unit reverts to the
indicated channel and RF ON state. The Alarm LED may be ON, which
indicates that there is no active video input.
Changing your Transmitter Configuration
The Palladium Transmitter can store up to 8 different configurations,
which can be selected with the Channel Control. Each of these configura-
tions can be programmed into the Transmitter with the supplied DTC
Programming Software and a Windows PC. Refer to the Programming
section on page 10 for more information.
To cycle through your preconfigured channels rotate the knob to the next
setting.
DTC COMMUNICATIONS, INC.
8
COMPONENTS
Audio 2 (left) and Audio 1 (right/mono) LEMO Conn. These connectors
provide the audio input connections to the transmitter. Either one or
two audio inputs can be used with the Palladium II Transmitter.
ALARM LED This red LED indicates a valid video signal is not
present.
Top Controls/Connectors
Multi-I/O Connector The Multi-I/O Connector is covered on page 9.
Data Chaining & Control Connector This connector is normally covered.
DTC COMMUNICATIONS, INC. 9
Palladium II
VIDEO TX
COMPONENTS
Transmitter Antenna Connector (SMA) This connector
attaches to the transmitter antenna and carries the RF
output signal. Always ensure the transmitter antenna
is attached before operating the Palladium Transmitter.
Muiti I/O Connector (6-pin Hirose) This connector
provides connections for the DC Power Input, DC
Camera Power, Programming, and 75 Ohm Composite
Video Signal.
1 Ground
Video In 75 Ohm 6
RS232 In 5
RS232 Out 4
2 +V Power
10V - 16V
3 Camera Power Out 10V -16V
DTC COMMUNICATIONS, INC.
10
PROGRAMMING
System PC Controller Application Software
Advanced control of the system is available by using the PC control
application software. Typically users may want to customize the default
configurations to control settings such as frequency, scrambling keys,
modulation parameters, and video resolution.
The transmitter is controlled by the application DTC_tx_ctrl_v1_3.exe
(or higher) available on the CD delivered with the product.
A PC is required with an available RS232 Serial COM port to control the
transmitter.
Installation of the control program is as simple as copying the file from the
CD to a suitable location on the PC. No install shield routine is launched.
Note that the application generates its own log and initialization files, so it
is best to create a dedicated directory for these applications, perhaps with
links to the applications from the desktop of the PC.
Getting Started
•Use the supplied programming
cable to connect the chosen COM
port of your PC to the transmitter
to be configured.
•Launch the application by double
clicking or using the Run...
command.
•Connection with a transmitter
should be automatic, but the user
can force selection of the correct
COM port using the drop down,
followed by the Connect button.
•Select the channel to be configured
from the unit’s front panel
Channel Switch.
•Click Refresh in the application to
display the current configuration.
•Update the current settings in the
application, then click Apply to
save to memory.
TELEMETRY
CHANNEL
Palladium II
VIDEO TX
Antenna
Audio
Battery Pack
Power Option
PROGRAMMING CABLE to
PC SERIAL RS-232 PORT
10 AA
BATTERY
PAC K
DTC COMMUNICATIONS, INC. 11
PROGRAMMING
Transmitter Control Application
Output Frequency (MHz)
The Output Frequency setting allows selection of TX output frequency in increments
of 0.250 MHz within the allowed tuning range of the unit. If the unit is set to a
frequency that is not an integer multiple of 0.25 MHz, the unit will be automatically
set to the closest frequency that is an integer multiple of 0.25MHz.
Modulation Bandwidth
Modulation Bandwidth is the actual channel bandwidth that the wireless video link
will occupy. The DVB-T compliant mode requires a bandwidth setting of 6, 7 or 8
MHz. The narrowband mode bandwidth is either 1.25 or 2.5 MHz. Narrower
bandwidths increase receiver sensitivity and extend the maximum distance of the
link, however video quality and latency will suffer. Normal default for good quality
video is 2.5MHz. The modulation bandwidth may be set to 1.25 MHz, 2.5 MHz, 6
MHz, 7 MHz, or 8 MHz.
Modulation Output
This control is used to turn ON and OFF the RF output. It must be ON for operation.
Turn the transmitter RF power ON by selecting ON and Apply from the application.
Narrowband FEC
Narrowband FEC sets the forward error correction rate in the narrow bandwidth
modes of 1.25 or 2.5 MHz. Tthe two rates are available are 1/3 and 2/3; the normal
default setting for good quality video is 2/3. Changing the FEC rate to 1/3 will
extend the receiver sensitivity by 2 to 3 dB at the
expense of degraded video quality and longer latency.
Narrowband Guard Interval
Narrowband guard interval is used in the narrowband modes of 1.25 and 2.5MHz to
adjust for varying multi-path delay conditions. The default is
1/16 however 1/8 can be selected if necessary to deal with extreme multi-path
delays on long links. Selecting 1/8 guard interval could cause a degradation in video
quality and latency.
Narrowband Modulation
Narrowband modulation is used in the narrowband modes to select between QPSK
and 16QAM modulation. For best range with good video quality, QPSK is used;
16QAM will give better video quality but will cut down the link range by
approximately 50%.
DTC COMMUNICATIONS, INC.
12
PROGRAMMING
DVBT Service Name
DVB-T service name is a place to assign a name for the DVB-T configura-
tion. Press Apply to save the new name.
DVBT FEC Rate
DVB-T FEC rate selects forward error correction rates in the wideband
DVB-T modes. Options are 1/2, 2/3, and 3/4, with 1/2 giving best range
and 3/4 possibly giving better video quality under certain conditions,
recommended default is 1/2.
DVBT Guard Interval
DVB-T guard interval selects guard intervals in the wideband DVB-T
modes between 1/32 and 1/4. Use the smallest guard interval that will
allow reliable low error rate communications, this parameter may need to
be adjusted when the link is relocated; the recommended default is 1/16.
DVBT Modulation
DVB-T modulation selects the modulation used in the wideband DVB-T
mode. Modulations QPSK, 16QAM, or 64QAM can be selected. QPSK will
give best distance and in most cases very good video quality and low
latency.
DVBT Spectrum Inversion
DVB-T spectrum inversion allows flipping the modulated spectrum to
compensate for spectrum inversion that may take place on the receiver
side due to high side LO injection.
DVBT 4 KHz Offset
DVB-T 4 KHz offset is not normally used but might improve BER in cases
where the TX upconverter I/Q balance is poor.
DTC COMMUNICATIONS, INC. 13
PROGRAMMING
Preset Transmit Mode
Preset transmit mode allows the user a convenient means of automatically
setting bandwidth, FEC, modulation and video frame rate/compression
based on link distance requirements. Options are: None (preset mode not
used), Short Range, Medium Range, Long Range, Ultra Long Range.
Output Power
Output power selects one of two output power attenuator settings; low
power or high power, typically the low power setting is the larger of the two
attenuator settings and is used, for instance, if a power amplifier is added
to the transmitter and the output power needs to be lowered substantially
to prevent overloading the input of the power amplifier.
Output Attenuation (dB)
Output attenuation (dB) is the high power attenuator setting.
This control can be used to make minor adjustments to the output power
level, but in normal operation should NOT be changed from factory
settings. (0 attenuation = full output power, greater than 0 attenuation =
reduced power in 0.25 dB steps.)
Output Attenuation low (dB)
Output attenuation low (dB) is the low power attenuator setting.
DTC COMMUNICATIONS, INC.
14
PROGRAMMING Video Input
Video input selects the video format going into the MPEG video compressor.
Options are: OFF (no video input typically used when link is used for data
only), PAL, NTSC, NTSC no pedestal, S-Video PAL, S-Video NTSC, S-Video
NTSC no pedestal.
MPEG Mode
MPEG mode selects the MPEG compression being used, options are: MPEG2
or MPEG4. MPEG4 mode has to be used when in the 1.25 MHz bandwidth
mode since this mode uses a nonstandard frame rate that is not supported
by MPEG2.
MPEG4 Encoding Mode
MPEG4 encoding mode selects the characteristics of the MPEG4 compres-
sion. Options are: low delay interlaced, standard delay interlaced, low delay progres-
sive, standard delay progressive, and SIF. Interlaced scanning is what is used in
conventional over-the-air video. Progressive scan is available on some cameras and
involves scanning an entire frame in one pass rather than two in interlaced scan-
ning. SIF is a bandwidth-conserving camera scan mode that cuts resolution in half
in both the horizontal and vertical.
MPEG4 Frame Rate
MPEG4 frame rate selects the frame rate used in the MPEG4 mode, full frame rate is
30 fps for NTSC and 25 fps for PAL a frame rate of 1/2 or less has to be used in 1.25
MHz bandwidth mode. Options are: Full, 1/2, 1/4, 1/8. or 1/24.
Video Bitrate (status only)
Video bitrate is a status window that will display the video transport data rate, this
varies with bandwidth, modulation, FEC rate and guard interval. The rate will
increase with bandwidth and higher levels of modulation, it will go down as the FEC
rate and guard interval are increased. The video bit rate will also decrease as other
service options are activated such as audio and data channels. As a rule video
quality and latency improve as the bit rate is increased.
Horizontal Resolution
Horizontal resolution determines the maximum number of horizontal Pixels that can
be sampled by the video encoder. For optimal performance this setting should be set
to the first value that exceeds the horizontal resolution of the camera in use.
Options are: 352, 480, 528, 704 pixels.
DTC COMMUNICATIONS, INC. 15
PROGRAMMING
Video Sharpness
Video sharpness is a filter that may be switched in to smooth out
blockiness in the video.
Audio Encoder
Audio encoder selects quantity of active audio channels (2 maxi-
mum), sampling rate (8, 16 or 32 KHz) which determines upper
frequency response, and sampling bits (8 or 12) which determines
audio signal to noise. Options are: Off, 8 KHz 8 bit stereo, 16 KHz
8 bit mono, 16 KHz 8 bit stereo, 32 KHz 8 bit mono, 32 KHz 8 bit
stereo, 32 KHz 12 bit mono, 32 KHz 12 bit stereo.
Audio Input Level
Audio input level selects the audio preamp gain level, options are:
0 dB, 12 dB, 24 dB, 36 dB, 48 dB. Use 24 dB for DTC supplied micro-
phones. Note: 3.5 VDC phantom power is at the microphone input for
powering electret condenser microphones.
Unit Name
Unit name allows the user to enter a name (up to 8 characters) for the
transmitter that will be stored in memory.
Sleep Mode
Sleep mode shuts down most functions in the transmitter except the
control functions. This can be used to conserve battery power and yet allow
the transmitter to become active again with a simple command.
Data
Data allows activation of the RS232 half duplex serial data channel and to
select parity mode.
Data Baud Rate
Data baud rate selects data channel baud rate, standard rates between
1200 and 115,200 baud are available.
DTC COMMUNICATIONS, INC.
16
PROGRAMMING
Chaining Input
Chaining input activates the chaining data port. This is not normally
used except in repeaters and high speed data transmission products.
Chain Number
Chain no. (not normally used) assigns a chaining tag number to the
stream associated with the transmitter’s video encoder. This can be
user-defined to 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9. Normally 0.
Chaining Output
Chaining output (not normally used) assigns the output of the video
encoder to the chaining port. Normally OFF.
Current Configuration
Current config indicates the preset that is currently being programmed or
viewed, this should be the same as the preset selected by the channel
switch.
Scrambling
Scrambling selects 3 different scrambling options: OFF (no scrambling),
AES128, AES256 (optional), or ABS (a proprietary 32 bit scrambling
algorithym).
Heartbeat Enable
Heartbeat enable activates a beating heart on the screen video graphic to
indicate that a link is still functioning even if there is no motion on screen.
NOTE: Chaining is digital
signal input and output
through the 16-pin Data,
Chaining, and Control
Connector.
DTC COMMUNICATIONS, INC. 17
PROGRAMMING
File
Change Logfile – opens a standard Windows file save dialog box which
allows the user to change the path and name of the log file generated by
the application.
Exit – exits the control application.
Options
Timeouts – password protected access to change timeouts used during the
serial communications between the unit and the controller.
Engineering – password protected access to further diagnostic and
calibration features.
Write License Code – open a further password protected box for entering
license codes for future upgrade.
Change RS232 address – Changes RS232 address of configuration port,
which is normally set to 1.
Write AES Key – opens a dialog box for entering a customer-selected
scrambling key. A key is a combination of 32 hexadecimal characters (64
for optional 256-bit encryption). Hexadecimal characters are 0, 1, 2, 3, 4,
5, 6, 7, 8, 9, A, B, C, D, E, and F. The receiver and transmitter must have
identical AES keys.
Restore Defaults – restores factory default settings in the transmitter.
User should NOT select Restore Defaults.
Polling Enabled – selecting this option makes the control application
automatically refresh the data presented to the user every few seconds.
Polling Options – selecting this option opens a dialog box for entering a
customer-selected polling interval (in milliseconds).
DTC COMMUNICATIONS, INC.
18
Physical
Unit Dimensions (approx.) 4.2” x 2.6” x 0.65” (not including connectors)
10.67 mm x 6.6 mm x 1.65 mm
Environmental
Operational Temp -10 degrees C to 50 degrees C
Power
Input Voltage 10 to 16 VDC
Power Consumption Fully Operational ~ 7.5 W, Sleep Mode < 0.5 W
Control
PC Control Interface RS-232.
Memory Eight user-programmable configurations
Video Encoding
Compression Standard MPEG-2 w/ non-DVB modes, MPEG-4
DVB-T Compliant
Chrominance Profile 4:2:0
Line Standard PAL 625 or NTSC 525
Horizontal Resolution 704, 528, 480, 352 pixels (528 as standard)
Vertical Resolution 576 (625 lines) or 480 (525 lines)
Video Bitrates 1Mbps to 10 Mbps
Video Latency End to end delay of 54 milliseconds
SPECIFICATIONS
DTC COMMUNICATIONS, INC. 19
SPECIFICATIONS
Audio Encoding
Input Stereo or Dual Mono pair
Bitrates 28 kbps to 72 kbps depending on configuration
Sampling Frequency 32 kHz, 16 kHz or 8kHz
THD < 0.1% max
Response 20Hz to 15KHz, +/- 0.25dB depending on
configuration
Crosstalk > 55 dB min
S/N 60 dB RMS
Composite Video Input
Standards NTSC (with and without pedestal) or PAL
Specification Rec. ITU-R BT.470-4
Connector Hirose
Composite PAL and NTSC decoding Eight-bit comb filtering composite decoder
Analog Audio
Analog Audio Input +10 dBu
Nominal Level +4 dBu
Scrambling
Scrambling type Fixed key scrambling system
Algorithms offered include AES.
COFDM RF output
Output Frequency Band Dependent
Occupied Bandwidth 1.22/2.44 MHz
Power 100 mW
Connector SMA
COFDM Standard Proprietary, 2.5 MHz channel bandwidth.
DVB-T 1.25 MHz
DTC COMMUNICATIONS, INC.
20
NOTES
DTC COMMUNICATIONS, INC. 21
NOTES
TWO YEAR WARRANTY
DTC Communications, Inc. (DTC) warrants its RF transmitting and receiving products to be free from
defects in workmanship or material for a period of two (2) years from the date of shipment unless
otherwise stated.
The liability of DTC, Inc. under this warranty is limited to replacing, repairing, or issuing credit, at
option, for any products, which are returned by the purchaser during such warranty period, provided:
DTC is notified and a Repair Authorization Number is issued by DTC Customer Service within 30 days
after discovery of such defects by Customer.
The defective units are returned to DTC with transportation charged Prepaid by the Customer.
Product damaged in shipment must be reported to and claim forms filed with the Carrier by the
Customer. In shipments to the factory, notice and claim procedures will be initiated by DTC.
DTC’s examination of such products shall disclose to its satisfaction that such defects exist and have
not been caused by misuse, misapplication, neglect, improper installation, improper storage, alteration,
physical damage or accidents.
The warranty shall not apply to material or accessories ordinarily susceptible to field damage or of a
disposable nature. Examples include batteries, antennas, microphones, headsets, cases, accessory
bags, etc. The warranty shall not apply to Engineering Prototypes or Customer requested modifications
to electronic circuits.
This warranty does not apply to and DTC does not independently warrant items or systems sold by DTC
which are produced by other manufacturers. With respect to such items, the Customer shall look to the
warranty of the original manufacturer and DTC disclaims all warranty, expressed or implied.
Nothing in this warranty, or any statement, brochure, bulletin, or advertisement is to be interpreted as
establishing the suitability of any product for particular application or use. Applications of the product
and the determination of suitability for any application, is the sole responsibility of the Customer.
CONTACT US
Contact Information
Nashua Main Office Numbers
486 Amherst Street
Nashua, New Hampshire 03063 USA
(T) 603 880-4411
(F) 603 880-6965
Toll Free in the USA
1-800 233-8639
Inside Sales
Law Enforcement
1-800 233-8639
Military
1-800 233-8639
OEM
1-800 233-8639
A complete listing of Contact
Individuals can be located on our
website at:
www.dtccom.com
REGIONAL SALES MANAGERS
Howard Rich
toll free (888) 819-8570
voice (860) 626-8570
fax (860) 626-8571
NY, MA, CT, RI, PA, NJ, MD, DE,
WV, DC
hrich@dtccom.com
Ed Bryant
toll free (800) 396-0295
voice (903) 725-7229
fax (903) 725-6952
CO, KS, OK, AR, NM, TX, LA
ebryant@dtccom.com
Joe Parkinson
toll free (800) 515-0599
voice (928) 443-9399
fax (928) 443-9302
CA, AZ, NV, HI, UT, AK
jparkinson@dtccom.com
Gary Nichols
toll free (866) 794-2823
voice (765) 473-8917
fax (765) 473-8920
MN, WI, MI, IA, MO, IL, IN, OH,
KY, NE
gnichols@dtccom.com
Frank Prioli
toll free (800) 246-2610
voice (727) 392-4761
fax (727) 320-0509
FL, GA, AL, MS, TN, NC, SC, VA
fprioli@dtccom.com
Phil Desmond
toll free (800) 233-8639
voice (603) 546-2217
fax (603) 880-6965
NH, VT, ME, WA, OR, ID, MT,
ND, WY, SD
pdesmond@dtccom.com
486 Amherst Street • Nashua, New Hampshire 03063 • 603-880-4411
www.dtccom.com
COMMUNICATIONS