Q-Lite Satellite Modem Installation and Operating Handbook
12-3
Scrambling – Closed
Network Plus ESC
32kbps or above: synchronised to ESC overhead.
Less than 32kbps: as per closed network.
V.35 Scrambler has CCITT, Intelsat, Fairchild and
Linkabit modes up to 55Mbps (with high Data Rate
options)
L-band connector Type
TNC female
L-band Impedance
50
Ω
L-band Return Loss
14dB Minimum
Internal Frequency
Reference - Ageing
<1ppm/yr
External Reference
Clocking Only: 1-10MHz in 1kHz steps.
Clocking and RF Frequency: 10MHz, 2dBm±1dB
12.2 Tx Modulator Specifications
Parameter
Modem
L-band Output Power
Level
0 to –30dBm continuously variable in 0.1dB steps
Output Level Stability
±1.0dB, 0ºC to 50ºC
Transmit Filtering
Spectral roll-off factors of 5%, 10%, 15%, 20%,
25% and 35%. See the document ‘Saving Satellite
Bandwidth by Optimising Spectral Roll-off’
(document number AN_035) from the White Papers
section of
http://www.paradisedata.com
) for more
details, including occupied bandwith calculations
Occupied Bandwidth
See referenced document AN_035 above
Recommended Channel
Spacing
See referenced document AN_035 above
Phase Accuracy
±2º maximum
Amplitude Accuracy
±0.2dB maximum
Carrier Suppression
-30dBc minimum
Output Phase Noise
As IESS-308, nominally 3dB better
L-band Output
Frequency Stability
±0.05 ppm per year
L-band Harmonics
Better than –60dBc/ 4kHz in band, no worse than
–45dBc out of band to 5GHz
L-band Spurious
Better than –60dBc/ 4kHz in band, no worse than
–40dBc out of band 10MHz to 5GHz
Transmit On/Off Ratio
65dB minimum
External Transmit Inhibit
By external contact closure or by TTL signal
applied to Utilities Card Alarms & AGC connector