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HSS-730/830 & UFD505/515 SERVICE MANUAL
3.3.1.3. Electrical Specification of Digital Tuner
Impedance
Return Loss
Frequency Range
Signal Level
AFC Range
Connector
Phase Noise
10 kHz
100 kHz
Synthesizer Step Size
Nyquist Shaping Filter
Symbol Rate
Inner Code
FEC Code Rate
Interleaving Factor
Outer code
Spectral Inversion
3.3.2. LNB Control
The LNB is powered through the center conductor of the RF coaxial cable connecting the LNB to
the STB. The polarization is switched by varying the power supply voltage of the LNB. In addition,
a 22kHz tone is used to switch the LNB between the low frequency band and the high frequency
band. The high frequency band is selected when the 22kHz is present.
The horizontal and vertical polarizations have different voltage ranges as shown in the below table.
Current
Vertical Polarization Voltage
Horizontal Polarization Voltage
Software Controlled LNB ON/OFF
The characteristics of the 22kHz tone is as follows:
Duty Cycle
Frequency
Amplitude
Rising and Falling Time
Software Controlled Tone ON/OFF
75 Ω
> 8dB
950 to 2150 MHz
-65 to -25 dBm
+ - 3MHz
IEC 169-24 female (F-type) and male (for loop-through)
< -70 dBc/Hz
< -90 dBc/Hz
PSK & BPSK (Compliant to DVB-S)
35% square root raised cosine
2 up to 45 Msps
Convolitional (K=7)
1/2,2/3,3/4,5/6,7/8. Automatically detected
I = 12
RS (204,188,T = 8)
Automatically detected
500mA max. (Short circuit protected)
13 to 14.5 V
17 to 19 V
Supported
50% ± 10%
22 kHz ± 4 kHz
0.6V (± 0.2V)
10 µs ± 5 µs
Supported
HDT DVB SATELLITE STB
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