For details about the front panel operation of the sat-nms LFTX optical transmitter card and sat-
nms LFRX optical receiver card please refer to the chapters
Local operation LFRX Card
and
Local operation LFTX Card
.
2.5.6 optional 75Ohm converter
The internal design of this unit is based on 50Ohm. To fit the sat-nms LFTXRX optical links to a
75Ohm system, internal 50/75Ohm converters with 75Ohm F-type connectors are available. Due
to its low loss design, this option causes approx. 1dB attenuation and approx. 1dB negative slope
over the hole L-Band. the internal DC bypass ensures the function of LNB power supply by an
optical transmitter card.
2.5.7 optional 1:4 splitter 'LFRXv4'
The sat-nms LFTXRX might be optionally equipped with internal passive 1:4 RF-Splitters, called
'LFRXv4'. These splitters are designed for dividing the received RF signal equally to 4 output
ports. They also might be used as passive combiners multiplexing different signals to an optical
transmit module. This option is available for L-Band only. Signals below 950MHz will be blocked
by this option and are not suitable for 10MHz or 50MHz...2150MHz broadband signals. The
'LFRXv4' Splitter option causes approx. 12dB attenuation and approx. 1dB negative slope over
the hole L-Band. The 12dB attenuation is caused by additional internal attenuation, therefore
unused ports do not have essentially to be terminated. A special Version with lower attenuation is
available on request.
Up to 10 'LFRXv4' might be installed to one sat-nms LFTXRX frame. It is also possible to equip
only some slots with this option to ensure maximum flexibility.
The splitter outputs come with 50Ohm SMA as standard, 75Ohm F-type connectors are available
on request.
2.5.8 optional dual coupler 'LFC10TX' and 'LFC10RX'
As an alternative for the optional 1:4 splitters (see chapter above) dual couplers are available.
These couplers provide the RF signal and additional 2 coupler outputs for e.g. monitoring
purposes. The mainline has approx. 1.5dB attenuation with approx. 0.5dB negative slope over the
whole L-Band. The 2 coupler outputs provide the mainline signal with approx. 10.5dB attenuation
and the typical coupler curve with approx. 2dB slope over the whole L-Band. Signals below
950MHz will be blocked by this option and are not suitable for 10MHz or 50MHz...2150MHz
broadband signals. The internal DC bypass on the mainline ensures the function of LNB power
supply by an optical transmitter card. The coupler outputs are DC blocked.
Due to the directional coupler design, different coupler types are available for transmit and
receive modules. 'LFC10TX' is designed to be used together with an optical transmit module,
'LFC10RX' is designed to be used together with an optical receive module. Depending on your
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www.satnms.com
LF20-UM-2107 Page 15/43
