LNB cu SCR

[genugeo85]

Am achiziţionat, de ocazie(f. ieftin), un lnb tip LNBFR8-Q(ACER) cu datele:
Frequenza ingresso 10.7 ÷ 12.75 GHz
Frequenza uscita 950 ÷ 2150 MHz
Frequenza oscillatore 9.75 ÷ 10.6 GHz
Guadagno 55 dB
Figura di rumore 0.3 dB
Attacco feed Standard 40 mm.
Frequenze uscite SCR Ch. 1 (1210 MHz)
Ch. 2 (1420 MHz)
Ch. 3 (1680 MHz)
Ch. 4 (2040 MHz)
Frequenze uscita universale 950 ÷ 1950 / 1100 ÷ 2150 MHz
SPLITTER 2 VIE
Frequenza 5 ÷ 2400 MHz
N. ingressi 1
N. uscite 2
(datele sunt luate de pe un forum italian)
Am inţeles că SCR=Satellite Channel Router. Imi poate explica cineva cum se foloseşte ieşirea SCR?
Mulţumesc anticipat!

[techcenter]

uita-te aici: http://www.st.com/stonline/books/pdf/docs/10465.pdf
sau aici: Single cable distribution. cred ca este vorba de ditributie tip single cable (sau unicable). sper sa nu ma insel.

succesuri!

---------- Post added at 22:13 ---------- Previous post was at 22:01 ----------

1.1 Description
ST Microelectronics has introduced a new device that targets the LNB, multi-switch and SMATV market. This device, called SaTCR-1 (Satellite Channel Router), is able to translate a transponder to any location in the satellite bandwidth (950-2150 MHz). Multiple SaTCR devices coupled with
band-pass filters and RF matrix allow to combine transponders from different polarizations and bands on a single coaxial cable.
The purpose of this document is to describe the AN2056 protocol extension used to control a LNB based on SCR technology.
1.2 Standard LNB versus SaTCR LNB
A Ku-band satellite can provide up to 4.1 GHz of useful bandwidth (2 polarizations x (12750 MHz
-10700 MHz)). A standard DVB-S tuner can receive frequencies from 950 MHz to 2150 MHz which means slightly more than 1 GHz bandwidth.

To be able to receive all the available channels in the Ku-band using a conventional LNB, a settop box has to select the polarization and the local oscillator corresponding to the desired transponder. The polarization is selected by changing the voltage of the LNB supply (13 volts for vertical polarization, 18 volts for horizontal polarization). The local oscillator is selected by adding or not a 22 KHz tone on the LNB supply (when 22 KHz in on the highest LO is selected). Local oscillator frequency can be 9750 MHz or 10600 MHz depending on the location of the transponder. If the respective transponder is in the lower part of the spectrum (<11700 MHz) the
9750 MHz LO is selected, otherwise 10600 MHz LO is selected. The tuner has to be set to the correct frequency using the following formula:
Ftuner = Ftransponder - FLO
With a LNB integrating SaTCR-1 devices, the transponder selection (polarization, LO selection and frequency translation) is done through a single DiSEqC command named ODU_ChannelChange



First stage of a SaTCR LNB (up to the matrix) is similar to a conventional LNB. As a consequence, the transponder frequency at the input of a SaTCR device is the same as Ftuner with a classical LNB:
Fsatcr_input = Ftransponder - F LO
Then, the SaTCR device should translate the transponder inside the bandwidth of its associated band pass filter. To perform that operation, the SaTCR VCO has to be set according to the following formula:
Fsatcr_vco = F satcr_input + Fbpf = Ftransponder - FLO + F bpf
In addition, SaTCR LNB includes new features that allow auto-detection of its parameters.
1.3 What does this mean for the set-top box?
1.3.1 Setup
The control of a SaTCR LNB requires more parameters than a standard LNB. Those parameters can be entered manually by the user or automatically detected by the set-top box. Automatic setup is recommended for all set-top boxes including tone detection capabilities (see Section 2.1 on
page 5).
1.3.1.1 Manual
In this mode, the set-top box should display an LNB setup screen where the user should enter the following parameters:
–• LNB type: the type of LNB used (see Table 3 on page 11 for SaTCR LNB application type)
–• Local Oscillator frequencies: depending on the LNB type, 1 or 2 frequencies should be entered
–• SaTCR band-pass filters frequencies: depending on the SaTCR application type, up to 8 frequencies should be entered.
1.3.1.2 Automatic
In that mode, the set-top box LNB setup screen should contain a button that launches the LNB auto-detection procedure (see Subsection 2.2: Detecting LNB parameters on page 5) using ODU_SCRxSignalON, ODU_Config and ODU_LOFREQ DiSEqC commands.

mai multe pe situl ST Microelectronics. www.st.com

succesuri!