Avalon RF OTX627 User manual

Avalon RF, Inc. • 344 Coogan Way • El Cajon, CA 92020
Phone: [phone] • Fax: [phone] • Email: [email protected]om
OTX627
COFDM Digital Video Transmitter
User's Guide & Operating Manual
REV. A – 14 Jan 2009
http://www.avalonrf.com/

AVALON RF, INC. Page ii
OTX627 Series User’s Guide & Operating Manual

AVALON RF, INC. Page iii
OTX627 Series User’s Guide & Operating Manual
Table of Contents
1. General................................................................................................1
Figure A – OTX Series Controls and Connectors.................................3
Video...................................................................................................4
Audio...................................................................................................4
Meta Data............................................................................................4
Talk Back Audio Channel (Optional)....................................................4
Two Way Digital Data Link (DDL) (Optional)........................................4
RF Outputs..........................................................................................4
2. Specifications & Interfaces...................................................................5
RF Specifications..........................................................................5
Video Specifications .....................................................................5
Audio Specifications .....................................................................5
Meta Data (Telemetry/User Data) (Option)...................................6
Control Interface...........................................................................6
Power...........................................................................................6
Connector/ Interface.....................................................................6
Physical........................................................................................6
User Interface......................................................................................7
Setup...................................................................................................7
Electrical Interface...............................................................................7
Table 2 – Current Consumption...........................................................8
Interconnecting..................................................................................10
Figure C – Power...............................................................................10
Figure D – Video................................................................................10
Figure E – Audio................................................................................11
Figure F – Data/Programming Input...................................................11
Mounting............................................................................................12
Mechanical Data................................................................................12
Figure G – OTX Series Mechanical Outline.......................................13
Environmental Conditions..................................................................14
3. Operating the transmitter. ..................................................................15
Operater Controls & Indicators...........................................................15
General Guidelines............................................................................17
Table 4 – Minimum Safe Distance.....................................................18
Warranty............................................................................................19

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OTX627 Series User’s Guide & Operating Manual
1. General
The OTX series rugged transmitters are intended for use in military,
homeland security, mobile security, broadcast and motion picture
production.
The OTX Series is a digital video transmitter using COFDM for robust
wireless video. The unit has 16 channels within a frequency range of
2.4GHz-2.483GHz and an optional extended range of 2.05GHz-
2.5GHz (for defense or licensed users only).
The transmitter carries video, stereo audio & data over the wireless
link. The data channel can be used for telemetry in UAV applications.
Some models have dual video inputs that can be used conveniently
with standard & night vision cameras. This is particularly useful for
robotic & UAV applications.
All transmitters offer the following features:
• A single broadcast quality video channel.
• Stereo audio.
• Meta-data @ 38.4kbps
• 4 power levels
Optional features (each ordered individually).
• Two-way UHF Wireless Data Link (WDL) to a ODX series receiver.
• Talk back audio channel.

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OTX627 Series User’s Guide & Operating Manual
1
5 3 2 4
Figure A – OTX Series Controls and Connectors
Top View
1 Main Antenna
Bottom View
2 Power/Video Input – see Figure C
3 Data Input – see Figures F
4 Video Input – see Figure D
5 Audio Input – see Figure E

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OTX627 Series User’s Guide & Operating Manual
10
9
7
8
6
Figure A – OTX Series Controls and Connectors (contd)
Side Views
6 Power Switch
7 Power LED Indicator
8 Status Indicator
9 RF Power Switch
10 Channel Select Switch

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OTX627 Series User’s Guide & Operating Manual
1.1 Video.
Depending on the model, the unit features either 1 or 2 video inputs.
The video inputs are standard 75 ohm impedance and accept
composite video with negative sync tips.
In case of dual video inputs, the switchover between Video A & Video
B can be made via a serial mode command.
1.2 Audio.
The audio interface is stereo. Both left & right channels are balanced
line level inputs. The input impedance is high – 100K.
1.3 Meta Data.
The transmitter also carries digital meta data with the video. The
standard baud rate is 38.4K with a 8N1 format.
1.4 Talk Back Audio Channel (optional).
The talk back audio channel allows the transmit side (e.g camera
operator on the transmit side) to receive instructions from the
operator at the receiver’s side. It drives an earpiece or the output can
be used with a PA system.
1.4 Two Way Wireless Digital Link (WDL) (optional).
The WDL serves as a Pan-Tilt-Zoom (PTZ) / general-purpose two-
way RS422/RS485 digital link.
1.5 RF Outputs.
The transmitters have two RF outputs (Only 1 for a standard unit,
without WDL or Talk Back Audio Option). A female SMA connector
for the main transmitter and a BNC for the WDL.
Both outputs feed antennas, either directly or through a cable.

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OTX627 Series User’s Guide & Operating Manual
2. Specifications & Interfaces
RF Specifications
RF Output: +27 dBm max. (3 selectable power levels)
RF Impedance: 50 ohms
Frequency Range: ISM bands - 900 MHz (902-928 MHz)
2.4 GHz (2.40 – 2.483 GHz)
Other frequency bands available in UHF, L band &
S band (for military, government or if user has
licensed frequencies) over the frequency range of
250 MHz – 2.7 GHz
Modulation: COFDM
Channel BW: 6,7 or 8 MHz
No of Channels: 16 channel capability
Modulation: QPSK
FEC: 1/2, 2/3
Guard interval: 1/32, 1/16
Video Specifications
Video Standard: NTSC or PAL
Video Input: Composite or Y/C
Video Compression: MPEG-2 Main profile @ Main Level
I, P and B frames supported
Video Resolutions: Full D1 (720 x 486 NTSC, 720 x 576 PAL) @ 30
fps; CIF or DVD
Bit Rate: 4 – 8 Mb/s depending on modulation parameters
Audio Specifications
Audio Input: Stereo inputs- Left & Right
Impedance: Balanced High Impedance 100K
Audio Compression: MPEG2 Audio
Bit Rate: 128Kb/s/ch
Sampling Rate: 48KHz

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OTX627 Series User’s Guide & Operating Manual
Meta Data (Telemetry/User Data) (Option)
Data Interface: RS232C, 8N1 setting
Baud Rate: 38.4K
Control Interface
Interface: RS232C, 8N1
Baud Rate: upto 38.4K
Usage: User loadable Frequency list of Channels through GUI;
SID (system ID settable for each channel)
Power
Input: 12V nominal; 9- 20V DC Unregulated
Consumption: 6W typical @ max. Output power of +27 dBm
Connector/ Interface
RF Output: SMA(f) 50 ohm
I/O Connectors
Power: 4 pin Lemo
Video: BNC (f) for single video unit; 2 x Mini-BNC(f) for 2 video
input unit
Audio: 5 pin Lemo
Data/ Control: 7 pin Lemo
Physical
Dimensions: Approx. 3.5” x 4.5” x 1”
Weight: Approx. 6.5 oz (180 gms)

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OTX627 Series User’s Guide & Operating Manual
2.1 User Interface.
a) On/Off Switch.
The OTX series transmitters have a electronic on/off switch. The
switch must be held pressed for at least 3 sec to turn the unit on or
off. This shuts off power to the entire transmitter.
b) Power on LED.
This is a red led to indicate the unit is turned on.
c) Status LED
The status led is bi-color and indicates normal operation or
programming mode.
d) Hands Free Back Channel (optional).
This option allows the receiver operator to communicate with the
transmitter operator via a headset that includes an earpiece and a
microphone, when the transmitter is on air.
2.2 Setup.
The OTX series transmitters have the following setups:
a) RF Channel.
b) Output Power Level.
2.3 Electrical Interface.
The transmitter has the following interfaces:
2.3.1 Power Input
a) The transmitter requires 9-20V dc. The power source can be
unregulated (like a battery) or a dc adaptor as long as the ripple
does not exceed 1Vp-p. When using a dc adaptor or powering
the unit from a vehicle battery, an external filter may be
necessary (depending on the situation) to provide reasonably
clean power to the transmitter.

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OTX627 Series User’s Guide & Operating Manual
b) The input is electronically switched and protected against
reverse polarity. There is also a ‘under-voltage lockout’
mechanism which ensures that there is at least the minimum
operating voltage present to turn on the transmitter. In case the
input voltage is lower than the minimum, the transmitter will not
turn on. The user will see only a brief flash of the red led.
c) Typical input current consumption for the basic configuration is
(with video present):
Model Output Power Input Current
OTX627 +27 dBm (0.5W) Approx 600mA
OTX627 +23.5 dBm (200 mW) Approx 450mA
OTX627 +20 dBm (100 mW) Approx 350mA
Table 2 – Current Consumption
Addition of option 11 (WDL) will increase the current draw by a
maximum of 170mA.
2.3.2 Video Input.
a) The video input accepts RS170, CCIR, NTSC or PAL signals. The
type of video input is set through the GUI provided.
b) Input signal is composite video 1Vp.p with a negative sync tip of
0.3V.
c) The input impedance is 75 Ω
ΩΩ
Ω (ohm).
2.3.3 Audio 1 and Audio 2 Inputs.
The audio inputs accept balanced line level signals of 1Vp.p. and
have an input impedance of 100K Ω
ΩΩ
Ω (ohm).
2.3.4 "Talk back" audio channel to the transmitter operator (optional).
The “talk back” output drives an electromagnetic earpiece (headset
speaker).

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OTX627 Series User’s Guide & Operating Manual
2.3.5 Two Way Wireless Digital Link (WDL) (Option 11)
The WDL is a 9.6KBaud (standard, other Baud rates are supported)
Half-Duplex RS485 compatible serial interface.
2.3.6 Main RF output to antenna.
The main RF output connector is a 50 Ω
ΩΩ
Ω (ohm) female SMA
receptacle.
2.3.7 Wireless Digital Link (WDL) RF output.
The WDL RF output is via a 50 Ω(ohm) BNC connector. Maximum
output power is +24 dBm (0.25W).
The main RF and the WDL RF outputs are identical on all the
transmitter versions.

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OTX627 Series User’s Guide & Operating Manual
2.4 Interconnecting.
All interfaces to/from the transmitter are available through the
following connectors:
2.4.1 a) Power Input.
Pin
Number
Function
1 Power Return (-)
2
3
4 Power Input (+)
Figure C – Power
b) Video Input.
Depending on the model, there is provision for 1 or 2 video input
signals. In case of the single video input, the connector is a 75 Ω
ΩΩ
Ω
(ohm) BNC while the 2 video inputs style has a 75 Ω
ΩΩ
Ω (ohm) Mini-
BNC connector.
Figure D – Video

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OTX627 Series User’s Guide & Operating Manual
c) Audio Input.
Pin
Number
Function
1 Audio Return
2 Audio L + Input
3 Audio R + Input
4 Audio R - Input
5 Audio L - Input
Figure E – Audio
d) Data/Programming Input.
Pin
Number
Function
1 Data GND/ Return
2 Program Signal 1(DO NOT
CONNECT/ USE)
3 Program Signal 2 (DO NOT
CONNECT/ USE)
4
5 RS232 In
6 RS232 Out
7 Data GND/Return
Figure F –
Data/Programming Input

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OTX627 Series User’s Guide & Operating Manual
2.5 Mechanical
2.5.1 Mounting.
Clamping (or hard mounting) is the only method of mounting
advised for all fixed installations. Avalon RF has a special
mounting plate available. Please ask for details. For mobile
camera usage, Anton Bauer mounting is also available at extra
cost. Please contact us for details.
The transmitter is designed for convection (free air flow) cooling
and no forced air-cooling (such as a fan) is necessary. The user
should simply take care to provide room for proper airflow. The
unit can be mounted on any side but it should not be sandwiched
between other equipment.
Another precaution to take when installing is to make sure there is
no source of strong electro-magnetic fields nearby.
2.5.2 Mechanical Data.
a) Size 3.07” x 1.73” x 1.0 (see Figure G)
78mm x 44mm x 25.4mm
b) Weight <5.6 oz.
<158 gram
c) Shipping weight <32 oz.
<900 gram

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OTX627 Series User’s Guide & Operating Manual
Figure G – OTX Series Mechanical Outline

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OTX627 Series User’s Guide & Operating Manual
2.6 Environmental Conditions.
The OTX Series is designed to meet the following environmental
conditions:
2.6.1 Operating temperature-4°to 122°F
-20°to 50°C
2.6.2 Storage temperature -13°to 150°F
-25°to 65°C
2.6.3 Vibration 1.5G, from 10Hz to 2KHz, sine wave, 3 axis
2.6.4 Shock 15G, 25msec, half sine wave, three axis
2.6.5 Humidity 5 to 95%, non-condensing
2.6.6 Inclination Any
2.6.7 Altitude -1500 feet to 15,000 feet
-450 meter to 4,500 meters

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OTX627 Series User’s Guide & Operating Manual
3. Operating the transmitter.
Before applying power, make sure all connectors and all antennas
are hooked up.
NOTE
The transmitter will not transmit unless it has an antenna.
3.1 The transmitter has three operator controls and two indicators:
a) On/Off switch.
The On/Off control is an electronic circuit & the switch must be
kept pressed for 3 seconds to turn the unit on or off. The electronic
switch also has ‘under voltage lockout’ that prevents the unit from
turning on or turns it off, if the input voltage is less than the
minimum voltage for reliable operation.
b) Channel select.
The unit has a 16-channel capability. The channels are pre-
configured in the ISM band (except for defense or export units)
with the most optimum settings but can be changed by the user
(authorized user’s only). The channel selection is through a 16
position rotary switch & numbered in hexadecimal format – 0
through F. In hexadecimal notation, A stands for 10, B for 11 and
so on.
c) RF Power Selection
The RF power switch is a 10 position switch with currently 3 power
levels available. The top 3 settings 7,8 and 9 have the maximum
power output for the model. Each lower setting is 3 dB (1/2) less rf
power. As an example, for the OTX627, settings 7,8 & 9 will have
the full +27 dBm (0.5W), setting 6 will be +24 dBm (0.25W) & so
on.
The user is advised to use the lowest power setting & increase
power only if the reception is poor.

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OTX627 Series User’s Guide & Operating Manual
d) Power LED
The power led is red & when lit, indicates the transmitter is on.
e) Status LED
This led is green during normal operation & yellow during
programming/ set-up.
3.2 The wireless data link is a secondary/utility link that is used to transfer
data/voice in the reverse direction. It is a narrow band UHF link
operating in the low UHF license-free band.
Following are the characteristics:
a) VOICE: Voice is transmitted from the receiver (ODX side) to the
Transmitter side (OTX side). It is implemented as a digital wireless
microphone and only the headset microphone is used on the ODX
side & only the earpiece is used on the OTX side. The microphone
is an electret mic.
b) DATA: The data rate is 9.6KBaud fixed (other data rates
supported) on a RS485 interface.

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OTX627 Series User’s Guide & Operating Manual
3.3 General Guidelines
The choice of a Transmitter and the Antenna to be used is dictated by
power consumption, required distance of operation of the link, if it is a
fixed or a mobile environment, the space constraints, the location
itself (indoors or outdoors, presence of nearby objects like trees,
bridges, etc.) and etc. Avalon RF will work with the user to determine
the right combination. Placement/positioning of the transmitter
antenna is important for proper operation of the wireless video link.
The antenna shipped with the unit is omni-directional, which means it
will radiate in all directions and when upright (vertical) will be
vertically polarized. The receiver side antenna’s then must also be
mounted vertically. While the above method would be the usual /
most common way, certain applications need a different placement.
As an example, to transmit between floors in a high-rise building, the
transmit & receive antennas can be small, directional, high gain panel
antennas, mounted horizontally, directly ‘looking’ at each other.
Circular polarized antennas are more expensive, but give a far better
performance, especially in mobile applications.
For proper operation of the wireless link, the transmitter antenna
should be kept clear of metal objects, trees, buildings, etc. If the
transmitter is mobile such as on a video camera, ensure the antenna
is sufficiently clear of the operator’s body, especially the head. A 2.4
GHz link is a line-of-sight communications, which means the receive
antennas should ‘see’ the transmit antenna.
Another very important aspect relates to health hazards from RF
energy absorption in the body. To minimize the risk, we ask that the
user ENSURE the minimum distance of the transmitting antenna from
the human body per Table 4. These values have been calculated per
FCC Bulletin OET65, Supplement C & related documents.