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Rack-Mount RDMS
TM
Telemetry Receiver
97
Quasonix, Inc.
Figure 171: Video Settings Window
4.2.3.1.2.8.1 NTSC Video Demodulation
While Quasonix RDMS™ receivers are primarily intended for digital data demodulation, analog FM waveforms can
also be demodulated.
When using the PCM/FM mode, base band analog from an FM digital appears on the I/Video A BNC connector.
The requirements for receiving analog FM are different from the requirements for receiving telemetry data and the
RDMS™ receiver has a number of controls that can be adjusted to optimize analog demodulation.
The primary controls are:
•
Mode
•
Bit-rate
•
IF filter bandwidth
•
Video Bandwidth
•
Video Scale
•
Video Invert
For demodulation of standard NTSC-Video, use the following settings.
On the Basic Settings window:
•
Mode - Set to PCM/FM to enable the FM demodulator
•
Bit-rate - Set to 3 Mbps
•
IF filter - Must be a minimum of 6 MHz (the actual filter used will depend on the number of IF filters
installed)
On the Advanced Settings window:
•
Video Bandwidth - Set to 6 MHz
•
Video Scale - Set to 0.25 to provide a 1V p-p video signal
•
Video Invert - Set to Off by default
If there are any spectral inversions in the system (such as a C to P band down converting antenna), Video
Invert should be set to On.
4.2.3.1.2.9 Additional Advanced Settings
Other settings are available on the Advanced Settings tab. When the receiver is in PCM/FM mode, four options may
be enabled or disabled by clicking on the checkbox next to the option. The options are Bi_Phase. Convolutional
Decoder, Spectrum Inversion, and DC Antenna. They are described following Figure 172. Only Spectrum Inversion
and DC Antenna are available for all other modes.