Druckschrift 99810560, Combiners and Filters for FM ... - Kathrein

Directional Filter Combiner
87.5 ... 108 MHz, 200 W
General
Directional filter combiners enable several transmitters
to be connected to one common output.
The design offers an expandable system which is
constructed in a modular form. The configuration
provides the best frequency response and optimum
isolation between the inputs.
Design and Construction
This combiner consists of two 3-pole band-pass filters,
two 3-dB couplers and a balancing load.
One input is narrowband (NB) in accordance with the
frequency response of the band-pass filters. The
second input is broadband (BB) within the operating
frequency range of the 3-dB coupler.
The directional filter combiner may be extended by
adding further combiners – directional filter combiners
as well as starpoint combiners.
Any heat produced is dissipated into the surroundings.
Thus the combiner is maintenance free and especially
safe to operate.
The band-pass filters must be tuned to the operating
channel. Tuning may be done at our factory or can be
carried out on site.
Clear tuning instructions and also any special tools
necessary are supplied along with the combiner.
790 277 FM Directional filter combiner, 200 W
Technical Data
Type No. 790 277
Output
Inputs Narrowband input (NB) Broadband input (BB)
Frequency range 87.5 ... 108 MHz 87.5 – 108 MHz
tuned to one channel free choice of channel
Insertion loss (1 < 0.8 dB < 0.2 dB
Input power 200 W 800 W
Channel spacing
> 1.5 MHz
Isolation
> 30 dB (NB to BB-input)
> 50 dB (BB to NB-input)
VSWR
< 1.1 (at pass band)
< 1.25 (at stop band)
Impedance
50 Ω
Temperature range –20 °C ... +50 °C
Connectors
7-16 female
Colour (front-plate)
RAL 7032 (grey)
Weight
34 kg
Dimensions
19″ drawer
(6 height units, depth 550 mm) (2
CH 1
Narrowband input
(NB)
Load
CH 2
Broadband input
(BB)
(1 Insertion loss and isolation values refer to the min. channel spacing of 1.5 MHz.
(2 One HU (hight unit) refers to 44.45 mm.
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