Grass Valley Digital Wireless Triax Camera System - Manual (Page 8)

8 User’s Guide - Digital Wireless System version 9
Technology
This wireless system combines with an LDK camera head to
form a Digital Wireless Triax Camera System. The high-
performance digital transmission means that the system is
omnidirectional with no adverse effects from multi-path
reflections.
The Digital Wireless Triax Camera System integrates perfectly
into your existing set-up. It is a flexible camera system that is
equally at home in the studio or out on location in an OB
environment. The bidirectional data transmission lets the
wireless camera communicate with LDK camera control
systems easily—just like a fixed-position LDK triax camera.
The ability to genlock the wireless camera, without a separate
frame store unit, ensures that the system can operate alongside
other cameras without timing problems.
The system uses a unique digital 4:2:2, 10-bit, end-to-end
signal using wavelet compression and DVB-T COFDM
transmission technology. This provides high-quality, reliable
pictures with very low latency. The extremely low latency
means that shots integrate seamlessly into the overall
production workflow with imperceptible video-to-audio lag.
No digital block effects are visible as with low bit-rate MPEG
transmission. Compression is intra-field, so all fields have the
same quality and there is no GOP (groups of pictures).
The received signal in a COFDM system can be improved by
multi-path reflections. To get the best benefits from reflections
the receiving set is equipped with a three antenna diversity
system. A set of three RF receivers is used to get the best
benefits of receiving COFDM signals via different reflection
paths (diversity principle). These down convert the RF signal
to VHF bands. The Antenna Management Unit selects
automatically between the receiving antennas without any
break in the RF link. Both transmitting and receiving antenna
are omnidirectional, so there’s no need for alignment or
tracking.
To extend the receiving area a second receiving set can be
attached to the Wireless Control Unit (WCU). The WCU selects
automatically between the two receiving sets without a
picture break (roaming).
Features
• Digital 10-bit 4:2:2 picture quality; close to wired Triax
cameras.
• Integrated Genlock as with wired Triax cameras; no
frame store needed.
• Perfectly clean frozen picture in the case of interrupted
video connection.
• Full camera control as with wired Triax cameras.
• Low power COFDM transmission.
• Automatic switching of multiple antenna sets.
• Extremely low latency.
• Selectable RF frequency; using several wide band
modules to cover ranges like 2.2 to 2.4 GHz, 2.4 to 2.5
GHz and 2.5 to 2.7 GHz.
• Most frequencies* in the ISM [2.4-2.5 GHz] band do
not require a licence (in E.U.).
• Easy frequency and channel selection from the
viewfinder menu of the camera.
• Full bandwidth audio channel or two channels with
reduced bandwidth.
• Excellent reception across 150m with a transmitted
power of just 40mW in open field conditions for ISM-
[2.4-2.5] GHz band. Increased power up to 75 mW for
other bands.
• AMU skate mount protects it from shocks.
• AMU sun cover reduces temperature increase.
A wireless system includes:
• A wireless camera adapter (including RF module and
two antennas).
• An antenna management unit (AMU).
• Three RF Receiver units with three matching antennas.
• Data emitter unit with matching antenna.
• An antenna bracket to mount RF and data units and
antennas.
• A 10m antenna cable set consisting of three coax cables
with BNC connectors and a RS422 screened cable with
a 9-pin D connector.
• A wireless connection unit (WCU).
For a complete digital wireless triax camera system the following
elements must be added:
• An LDK camera head and viewfinder
• A lens
• Triax and control cables
For full remote control:
• An OCP
• An MCP
To expand the operating range of the camera an additional
AMU with antenna set can be added to the system.
* some do; refer to the frequency table in the section “Setting
up the camera adapter”