A. Basic modular version

CHANNEL RECEIVING UNIT SC-RSS-201

Channel Receiving Unit SC-RSS-201receives frequency modulated TV signals in TV cable networks and in systems to transmit TV signals on microwave links.
Receiver SC-RSS-201 is supplied in the following versions:
SC-RSS-201/ST - basic configuration (1 audio stereo channel, a video filter without an envelope delay corrector)
SC-RSS-201/DS - same as the /ST configuration, but with two audio stereo channels
SC-RSS-201/ST-LX or DS-LX a super video filter with an envelope delay corrector
SC-RSS-201/AL - to be used in microwave links
SC-RSS-201/ALS - special configuration for microwave links (audio 7 MHz)
SC-RSS-201/19 - channel receiving unit in 19” rack, mostly in configuration SC-RSS-201/DS-LX.

The device is in its standard version used to install in the supporting rack or a board in the vertical position, in the configuration /19” it is installed in the standard 19” rack in the horizontal position. Upon request other circuitry - like symmetric audio outputs, output audio and video levels regulation, remote control, other functions on the display - may be added in the version SC-RSS-201/19”.

The receiver unit is controlled by a single-chip microprocessor of the ST series through an I²C bus. It controls all frequency synthesis PLL circuitry, input filter bandwidth switching, video filter switching, video deemphasis switching and regulation of audio parts of Channel Receiving Unit SC-RSS-201. The channel frequency appears on the display after being connected to the Power Supply Unit (NZS-15). The functions are selected with MODE button. Channel Receiving Unit SC-RSS-201 is connected to an external unit through a convenient feeding unit (like Feeding Switch LNB SPI-1750) and Branching Units, if any, like SAP-2, SAP-4 etc.). The coaxial cable terminated by an F-connector (a plug) shall be connected in the F-connector (a socket) in the top side of the cover. The output signals are drawn from the relevant connectors in the front panel.

The channel receiving unit can serve as a video and audio signal source for various external devices or for other SATCO units like TV Modulators SC-M-101 and SC-STM-208, Satellite Radio Demodulator SC-ASR-206, UHF Stereo Modulator SC-SFM-101 and the like. When the Balancing Amplifier SC-ASZ-101/SO is used, then balanced L.F. signals to feed other L.F. equipment can be acquired.

SC-RSS-201 Basic technical data:

received signals features:

H.F. parameters:

Video parameters:

Audio parameters:

General data (modular version):

SC-STM-208 - basic modular version
SC-STM-208/19”- basic version in 19” rack

Versions according to output frequency:
VHF output frequency in 47 MHz to 446 MHz band
UHF output frequency in 470 MHz to 862 MHz band
KU output frequency in 5 MHz to 30 MHz band (reverse channel)
MF output frequency in I.F. band, video carrier 38.9 MHz or 38.9 MHz (I.F. output without conversion in TV channel)
MF2 I.F. output with separated outputs for video carrier and audio carrier without conversion in TV channel - (only in 19” version)

When ordering versions VHF, UHF and KU, the requested standard CCIR either B/G (audio 5.5 MHz) or D/K (audio 6.5 MHz) and required output frequency are to be specified.

Accessories upon request (all versions):
VIF.: equipped with a video filter and a group delay corrector

Accessories only for the 19” version:
XLR: equipped with symmetric audio input XLR 600 W (stereo)
DO: equipped with remote control by a PC
EXT: External synchronizing frequency input
REG: equipped with regulation of input audio levels or subcarrier levels (for MF and MF2).

The input video signal is amplified in a video amplifier and after eventual correction in a video filter with a group delay corrector is brought in an AM modulator operating on frequency of 38.9 MHz. This signal is amplified and adapted in a filter block. A signal to decode a VPS signal is diverted from the video signal. The audio signal goes through preemphasis and audio filters circuitry in matrix circuitry, electronic switches circuitry and circuitry of an identification signal generator. These signals modulate I.F. modulators operating in 32.4-33.4 MHz band. After merging with the video carrier, the signal goes in a mixer, and the signal of the relevant TV channel appears in output of the mixer. After filtering parasitic products and appropriate amplifying, the signal goes in an RF OUT output connector.

Command, control and connected elements are situated on the front panel. Frequencies of the video carrier oscillator 38.9 MHz, of both audio modulators and of the main oscillator are stabilised by PLL circuitry. Reference frequency for the PLL circuitry is brought from a crystal driven oscillator. In the 19” version, the reference frequency can be brought from an external source 4.0 MHz, 6.4 MHz or 8.0 MHz. In such a case the precise offset of output frequency in multiples of 1/6 of horizontal video frequency can be adjusted.

Front panel diodes signalise the operating mode. L16F signalises that the VPS signal is present, ST and DUO indicate the operating mode. The operation parameters appear on the display and some of them can be adjusted with buttons. The Mode button enables to switch between the operation mode (according to the transmitted VPS data line) and the manual mode (manual selection stereo, mono and duo modes), to display video carrier frequency, to change separation between audio carriers and a video carrier, they indicate the VPS and PLL statuses. The modulator activity is controlled by a microprocessor. Output H.F. signal goes in an F-connector and its level is regulated by a RF LEVEL regulating element.

SC-STM-208 Basic technical data:

1. Output signal parameters:

   video carrier output level		108 dBm V
   protected frequency zone		30 to 862 MHz
   ripple factor of output frequency response		< 1 dB
   video carrier output level stability		< 1 dB
   min. signal to noise separation		58 dB
   output impedance		75 W

2. Input signal parameters:

   nominal input level		0 dBr
   input impedance		> 30 kW
   frequency range		50 Hz to 15 kHz
   L.F. preemphais		50 m s

3. Transmission and modulation parameters

   nominal intermodulation level		85%
   intermodulation level stability		± 5%
   differential gain		3%
   differential phase		3°
   difference in gain colour / brightness		1 dB
   video amplitude-frequency responsein band to		4.43 MHz +1 dB / -1.5 dBto 4.8 MHz - 3 dB
   L.F. signal amplitude-frequency response		+1.0 dB / -3.0 dB

4. General properties (modular version)

   weight		1.2 kg
   dimensions		42 x 146 x 292 (367) mm
   supply voltage		± 15 V (+1V/-0.3V)
   power connector		WAGO 231-xxx and like
   input connectors		CINCH
   output connector		F socket

The SC-ASR-206 demodulator is supplied in the following versions:

- SC-ASR-206/ST basic version in modular configuration

- SC-ASR-206/AL version for application in microwave links

- SC-ASR-206/19 version in 19” rack, possibly with another SATCO unit

The device in its standard modular version is to be installed in the supporting rack or a board in the vertical position, in the configuration SC-ASR-206/19 it is installed in special holders for 19” rack in the horizontal position. Other circuitry can be provided upon request - like symmetric audio outputs, a change of the audio subcarrier frequency range, additional functions on the display. The operation of the SC-ASR-206 demodulator is controlled by a processor. The front panel functions can be switched using the MODE button. These are the received signal frequency for the left channel, the received signal frequency for the right channel, expander ON and OFF, switching bandwidths of the I.F. filter and of audio preemphasis. The input signal containing audio subcarriers (ie a baseband type signal) is brought in the input BB IN connector. This connector is connected with the BB OUT output connector through a switch. These two connectors can be connected either directly or through a low pass filter. Such connection enables to put several SC-ASR-206 units in a cascade channel.

Audio subcarriers go from the BB IN connector through a high input impedance amplifier in a band pass filter with pass band approx. 5.5 MHz to 9.0 MHz (or a low pass filter to 5.0 MHz). The signal is divided in two independent branches behind it, labelled as LEVý Kanál (left channel) and pravý kanál (right channel), that serve to process two independent or stereo channels.

The output signal goes through a regulation amplifier into a low pass filter with limit frequency approx. 18 kHz which should suppress ultra-acoustic components of an L.F. signal. The L.F. signal branches in two paths then. In the first, a compressed signal goes through expander and deemphasis circuitry in the first input of a change-over switch. The other path processes an uncompressed signal. It passes switchable deemephasis 0 m s, 50 m s (16), 75 m s (17), J17 (18) circuitry and goes into a regulation amplifier and the second input of the change-over switch. The switch selects the signal to be processed either through an expander or linearly. The signal goes from the switch through an input L.F. amplifier in Audio out output cinch connectors on the front panel and audio aux output DIN connectors on the top side of the cover.

SC-ASR-206 Basic technical data

Parameters for input signal:

Basic transmission parameters:

General properties (modular version):

- SC-IC-101/UHF 470 to 862 MHz

- SC-IC-101/VHF 47 to 470 MHz

- SC-IC-101/KU 5 to 30 MHz (reverse channel).

The input signal is fed to an adjustable attenuation element with PIN diodes. A band pass filter tuned to the input signal frequency follows. The amplifier amplifies the received signal to the level required and balances loss in band pass filters. Another band pass filter increases the input circuit selectivity and therefore provides the adequate rejection of parasitic signals and external noise immunity. An amplifier and a balanced mixer follow behind the second band pass filter. A local oscillator signal is brought in the other input of the mixer and its frequency is fixed and stabilised by a frequency synthesis PLL circuit.

The input signal is converted to the intermediate frequency in the 32.15 - 40.15 MHz band in the mixer. Behind the mixer, a frequency filter follows that suppress higher harmonic frequencies, the oscillator frequency and other undesirable products, if any. The intermediate frequency signal is amplified in an integrated adjustable gain amplifier and fed in the output connector. This filter is of the low pass type usually. At worsened receiving conditions, particularly at processing adjacent and next-to-adjacent channels, the input unit can be complemented with a SAW filter upon request.

Input Unit SC-IC-101 is supplied also in the version SC-IC-101/AV with an input TV signal demodulator. It contains an independent synchronous video modulator and an independent audio subcarrier demodulator. The demodulated output video signal and the audio signal are brought in the CINCH connectors on the front panel.

The device is powered from an external source +15 V (like NZS-15 type, supplied by SATCO s.r.o. company).

Data of the input unit SC-IC-101 itself:

SC-OC-101 is supplied factory adjusted at a fixed channel. The following SC-OC-101 types can be distinguished according to the frequency range of the output channel

- SC-OC-101/RP 47 MHz to 446 MHz

- SC-OC-101/UHF 470 MHz to 862 MHz

- SC-OC-101/KU 5 MHz to 30 MHz (return channel)

The output unit of the frequency converter is powered from an external source +15 V (like NZS-15 type, supplied by SATCO s.r.o. company).

The input I.F. signal from SC-IC-101 goes to an adjustable damping element with PIN diodes. A low pass filter and band rejection filters, a compensating repeater and a band pass SAW filter follow. Another balanced amplifier amplifies the I.F. signal to the level convenient for the mixer and also enables to adjust the basic gain of the complete I.F. circuit and feeds the automatic gain regulation circuitry AGC. These circuitry consists of a peak detector, a deviation amplifier with an adjusted regulation level and an adjustable damping element with PIN diodes. The regulation voltage is brought through a front panel switch (position “AGC”). The automatic regulation is off in the “MAN” position and gain is adjustable only using trimmer MAN accessible through a front panel circuit.

The I.F. signal is brought through another band filter in a balanced mixer. The local oscillator signal is brought in its second input and its frequency is given and stabilised by a PLL frequency synthesis circuit. The signal is converted on the frequency of the desired TV channel in a mixer. Behind the mixer, there is trap circuitry for the frequency of the oscillator and of the second basic mixing product. The next regulation amplifier enables to adjust the output signal amplitude. The regulating element has a connection to the front panel where it is labelled as “RF OUT”. The signal goes through a main band pass filter, an amplifier and another band elimination filter to a terminal output amplifier. Then the signal goes through an output filter and a matching element to a output connector labelled OUTPUT. The output is of the “wideband” type with output impedance 75 W .

Data of the output unit SC-OC-101 itself:

The stereo UHF modulator consists of one unit that contains a stereo coder and an FM modulator. The audio signal goes into an input impedance switch and an ON/OFF damping element (-6 dB), into an adjustable gain amplifier. Then switchable preemphasis 50 m s or 75 m s and a Cauer-Chebyshev low pass filter with cut off frequency 15 kHz follow.

A stereo coder with circuitry to compensate cross talk and harmonic components of multiplex signal follows. Then a summation amplifier, a low pass filter for multiplex signal and an output amplifier. Control signals for the stereo coder are generated digitally by a crystal controlled oscillator. The pilot signal can be switched off. The pilot signal level and phase are adjustable. The multiplex signal goes through an excursion regulator into a FM modulator operating at 10.7 MHz.

An isolating amplifier follows that branches the signal in two, then an adjustable attenuator, an amplifier, a ceramic filter with bandwidth 280 kHz, an isolating amplifier and a fixed attenuator -4 dB. The I.F. signal passes in a mixer then.

There is an isolating amplifier in the other branch from which the signal goes in the frequency synthesis outlet. Control voltage goes in a FM modulator that is being tuned to the nominal frequency. Behind the mixer, there are an amplifier with controlled gain, a band pass filter and a parasitic signal trap, then a terminal repeater follows.

The main oscillator signal is brought through a predivider in the PLL frequency synthesis circuit. An input impedance switch for 600 W and preemphasis 75 m s shall be built in according to customer´s requirements.

a) output signal basic parameters:

b) input signal parameters

c) Audio signal transmit. parameters

d) Access points:

e) General data

The input signal is converted on intermediate frequency 10.7 MHz. It is filtered and converted back in the UHF band. The input is of the input-output type with impedance 75 W . The received signal goes through three band pass filters in the first balanced mixer and it is mixed with the signal from the first oscillator into I.F. frequency. Frequency of the first oscillator is stabilised by a PLL frequency synthesis circuit. Behind the first mixer, there is an I.F. amplifier with frequency filters with switching bandwidth (280 or 150 kHz).

The signal goes through a limiting amplifier and then it is divided. The first part of the signal is demodulated and goes either as monitoring one directly in the MPX output or from a 50 m s deemphasis circuit in an AUDIO OUT output. The other part of the signal is amplified, filtered and brought in the second mixer. Here, the I.F. signal is mixed with the signal of the second oscillator that is driven and stabilised by a frequency synthesis circuit. The output signal is converted in 87.5 to 108 MHz band. Output signal frequency can be adjusted in this band with 100 kHz increment. Behind the mixer, the signal goes through tunable filters and a trap circuit in output. One of the amplifiers is a controlled-gain one. The output level is adjusted on the front panel using this amplifier.

On the front panel, there are three control buttons and a display that indicates input frequency and bandwidth (280 or 150 kHz). The buttons control output frequency and bandwidth. The typical range of output signal level regulation is 12 dB. On the front panel, there are all input, output and power connectors. The converter is powered from an external +15V voltage source (like NZS-15 type, supplied by SATCO company). The UHF converter activity is controlled by a microprocessor. The tuned-up data are saved in an EPROM memory. Output frequency is adjustable continuously, input frequency is factory adjusted according to customer´s requirements. Input is of the transmission type with branching which allows UHF converters to be used in the configuration without using a branching device.

The input signal is brought from the input connector in a Cauer band pass filter, then a nominal gain switch follows by which either a damping element (gain 30 dB) or a pre-amplifier (gain 50 dB) is put in the signal path. Then there are a trap circuit for III TV band and a PIN attenuator to change gain in range 0 dB to -40 dB in comparison with the nominal value set by the gain switch. A low level amplifier follows behind the PIN attenuator and part of it is a parasitic signal trap. Behind the amplifier, there are a matching filter, a terminal amplifier with an output level detector and an output filter.

There are two switches and three adjustable several-turn resistors on the front panel of the UHF band amplifier. These regulation elements enable the operator to select a nominal gain, an operation mode (manual or automatic gain control), to adjust the output signal required level and to adjust the wave trap. There are input, output and feeding connectors on the front panel. The device is powered from an external +15V voltage source (like NZS-15 type, supplied by SATCO s.r.o. company). The amplifier has nominal gain 30 dB and 50 dB, which can be selected by a front panel switch. It can operate in two modes:

• MAN: linear gain, its magnitude is given by the switch 30dB/50dB position. The gain can be continuously decreased by a regulating element LEVEL MAN with damping 0 dB to -30 dB.
• AUTO: automatic control of output level is selected which according to the input signal level controls gain in such a way that the output level is kept at the preselected value in the range 109 dBm V to 97 dBm V.

The amplifier is provided with a NOTCH wave trap that is used in case that one of the signals level is higher than other. The wave trap can be tuned in 65 MHz to 130 MHz band.

with frequency up to 700 MHz automatically or manually. It can be used also to switch modulating audio and video signals. Particularly it serves to switch signals from various sources, to backup signals and the like. It is supplied either in the basic modular version or upon request in the standardised 19” racks (only in the 2V configuration).One switch can contain two or four switching sections. More sc-ssw-101 units can be mutually grouped. After the switching sections are mutually grouped, one switch can switch up to five signals in one output.

The switch is supplied in three basic configurations:

- SC-SSW-101/2R contains 4 universal switches

- SC-SSW-101/R contains 2 universal switches

- SC-SSW-101/2V contains 4 switches of audio and video modulation signals

The switching sections operate independently but they can be grouped functionally for some applications. The switching sections of more sc-ssw-101 switches can be grouped, too. Each switching section contains two input and one output connectors. One connector, labelled IN A, is always a priority one. In the 2V configuration, there is identified only the presence of a video signal by analysing synchronising pulses. In the R and 2R configurations, this input is equipped with three modes of signal presence identification that can be selected using a rear-side switch, for each section independently:

- video signal in the baseband,
- H.F. signal modulated by video signal
- unmodulated H.F. signal.

As soon as the selected signal is not present in the IN A connector, the switch switches in the IN B position while continuously following IN A and when the signal appears it switches back in this basic position after some time. The switch is provided also with a CANNON 15 connector where the input and output logic control signals lead. With this connector, manual selection, remote signalling and functional grouping of the switching sections are realised. The manual mode can be used e.g. for purposes of a local information channel.

The switch is powered from an external source +15 V (like NZS-15 type, supplied by SATCO s.r.o. company).

Identification of signal presence in automatic switching mode

1. Using synchronising pulses of normalised positive video signal 1 Vpp
2. Using synchronising pulses of H.F. TV signal above 38 MHz (min. H.F. carrier level 85 dBm V)
3. Using the level of H.F. carrier itself, switch-on and -off levels are adjustable, the nominal level is 85 dBm V. The mode can be used particularly for a FM signal.

The identification mode for each section is selected using an independent two-position switch (synchronising pulses - level).

Manual control

CANNON 15 connector, level control, TTL levels, negative logic. Three PINs belong to each section:
inputs - selection between manual and automatic control,
output - switching section status, effective to chain sections or for remote indication of switch action,
switching - possibility to switch the section in the manual mode
If the connector is not connected, all sections are in the automatic switching mode according to the priority signal parameters.