Contemporary Research QMOD-SDI User Manual
QMOD™ Integration Tips
QMOD-HD HDTV Modulator
QMOD-HDSC Scaler Modulator
QMOD-SDI HD-SDI Modulator
June 6, 2011
Contemporary Research 1 QMOD-HD Integration
Table of Contents
Overview ............................................................................................................................................... 3
How Does it Work? ..........................................................................................................3
Source Integration................................................................................................................................ 4
HD Component Source .....................................................................................................4
AV Video Source..............................................................................................................4
DirecTV Tips ...................................................................................................................5
VGA Source ....................................................................................................................5
QMOD-HD/TV1 System .............................................................................................................................5
QMOD-HDSC .........................................................................................................................................6
SDI Source (QMOD-SDI) ..................................................................................................6
Encoding and RF Settings ..................................................................................................................... 7
Basic Troubleshooting........................................................................................................................... 9
RF Integration..................................................................................................................................... 10
Combining Channels ......................................................................................................12
Inserting Channels ........................................................................................................12
Using and Measuring RF Output Levels .............................................................................13
Distribution and Attenuation ...........................................................................................15
Splitters and Combiners ..........................................................................................................................15
Active Combiners and Amps ..............................................................................................................15
Taps......................................................................................................................................................16
Cable.....................................................................................................................................................16
Factoring Levels..................................................................................................................................17
Resources.....................................................................................................................18
Integrating Control ............................................................................................................................. 19
Design and Install Using Three Components .....................................................................19
Contemporary Research 2 QMOD-HD Integration
Overview
CR QMOD™ technology is opening the door to new HDTV applications.
broadband RF over coax isn’t just for TV anymore. The broadband network that exists in many
sports, commercial, education, and civic facilities can be re-tasked for distribution of in-house highdefinition video and audio from HD satellite and cable receivers, IP and microwave driven media –
and digital signage.
A few years ago, this type of technology required a $30,000 investment per channel, down to
$15,000 a year later, and is now a practical, commercial solution for less than $2500 a channel. At
that cost, a wide range of new distribution and integration opportunities are possible.
Thanks to CR innovation,
How Does it Work?
While the technology is pretty amazing, the chips and codecs that make the magic work are now
available at a practical price. Older technology involved a number of separate, expensive
components. In the QMOD-HD, the entire solution is integrated into one HDTV Modulator:
Analog to Digital Converter scans the selected video input and converts to digital packets
MPEG-2 Encoder – high-performance DSP merges video and audio into an MPEG-2
transport stream
QAM Channel Modulator fast FPGA chip formats the stream into a 64 or 256 QAM digital
cable channel
Upconverter/Amplifier sets the channel to a specific number, then amplifies for
distribution through the RF system, typically up to 30 dBmV
Contemporary Research 3 QMOD-HD Integration
Source Integration
HD Component Source
The most common application for QMOD technology is to distribute the output of an HD satellite
receiver or cable box.
Connect the Component YPbPr video between the two units, then either TosLink optical,
coax digital or stereo audio outputs to the QMOD.
Set the receiver to 720p or 1080i (or SD 480p)
Configure the QMOD inputs using the Setup, Arrow, and Select buttons on the front – the
LCD text will display the various menus and options
o Select the Component (YPbPr) input
o
Select the Audio input
o
Select the resolution to match the output of the source
o
Select the planned channel for the RF system (2-1 to 135-1)
Connect the RF Out to a nearby display, tune to the selected channel to preview
As an option, you can use a BNC to HD15 VGA cable to provide a locking connection
between QMOD and BNC Component sources. The RGB pins on the QMOD HD15 input are
cross-wired to the YPbPr inputs –just connect and set QMOD to
The same applied to scalers that can output YPbPr on their HD15 output – use a VGA cable
to YPbPr
AV Video Source
The QMOD can also handle SD video on the S-Video or composite video input at 480i. For S-Video,
use the Video input for the Y, the blue Pb input for C.
Connect the source to the Video and Audio inputs, and update the QMOD settings. You don’t need
to change the Video Format – Video and S-Video are fixed at 480i.
Contemporary Research 4 QMOD-HD Integration
DirecTV Tips
For best performance, go to the receiver’s Setup/HDTV menus and:
Go to Video and turn the Native mode Off (otherwise, video can revert to 480p)
Go to Resolution and turn off all resolutions but 720p (Native Off doesn’t work in 1080i)
VGA Source
VGA output is handled differently, for several reasons. Similar to video projection, using a Scaler
allows you to format the video exactly how you want it to be seen, instead of off to the left, right,
up, down, chopped off, too small or not at all.
VGA 1920 x 1080 and 1280 x 720 are very different standards than 1080i or 720p
Some digital signage PCs are fixed at other resolutions, and some are 4:3 instead of 16:9
The frequency of the signal is rarely accurate, needs to be 59.94 Hz
The graphics of the signage presentation may run to the edges, and need to be under-
scanned to fit the graphics for use with HDTV displays
For that reason, almost all PCs require a VGA Scaler that can output 1080i/720p HD at 59.94 Hz.
QMOD-HD/TV1 System
For the QMOD-HD/TV1 System, we use the TV One 1T-C2-400 to condition the VGA video to HDTV
standards, and to position and format the output - many displays overscan video, so sites often
underscan the signage video in the scaler to compensate. Get the QMOD-HD/TV1 Install Guide for
more information.
Otherwise, integration for VGA is similar to Component.
Connect the VGA output to the Scaler
Set the Scaler for 1080i or 720p output
Connect the Scaler VGA to the QMOD VGA input
Connect the stereo output of the PC to the QMOD, or digital audio if available
Configure the QMOD inputs using the Setup, Arrow, and Select buttons on the front – the
LCD text will display the various menus and options
o
Select the VGA input
o
Select the Audio input
o
Select the resolution to match the output of the source
o
Select the planned channel for the RF system (2-1 to 135-1)
Connect the RF Out to a nearby display, tune to the selected channel to preview
Use the external Scaler menus to position, resize, or underscan as needed.
The setup would be similar for the QMOD-SDI, with a scaler feeding the Component inputs, using
an HD15 VGA to RCA Component adapter cable, and the scaler set to Component output.
Contemporary Research 5 QMOD-HD Integration
QMOD-HDSC
The QMOD-HDSC has an internal scaler, so the setup is much simpler.
Connect the VGA output to the QMOD-HDSC
Connect the stereo output of the PC to the QMOD, or digital audio if available
Configure the QMOD inputs using the Setup, Arrow, and Select buttons on the front – the
LCD text will display the various menus and options
o
Select the VGA input
o
Select the Audio input
o
Select the resolution to match the output of the source
o
Select the planned channel for the RF system (2-1 to 135-1)
Connect the RF Out to a nearby display, tune to the selected channel to preview
Use the QMOD-HDSC menus to position, resize, or underscan as needed.
SDI Source (QMOD-SDI)
The new QMOD-SDI has the same Component, Video and Audio inputs as the QMOD-HD, with the
addition of an SDI input in place of the RGB connection.
One you select SDI as the input, the QMOD-SDI will automatically adjust to the input’s resolution
(1080i, 720p, or 480i). The audio is often embedded in the stream, and you can use the stereo and
digital audio inputs when the audio is separate.
Use of 64 and 256 QAM
We use 256-QAM as the default setting because some makes of onboard display tuners can’t tune
64-QAM. 64-QAM can be a solution where there is RF noise that affects 256-QAM, and displays
have compatible tuners.
Contemporary Research 6 QMOD-HD Integration
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