FM COMBINERS

Combiners are used to join the signals of several transmitters into one common antenna system.
Star-point combiners (type A) represent compact and cost effective solution when there is a large channel spacing between the transmitters. In the star-point configuration is possible to connect up to four band-pass filters. Star-point combiner is pre-tuned in factory on requested frequencies, but it is also easily retunable on the transmitting site. 
Constant impedance type of combiners (type B) consists of pairs of 3dB couplers and band-pass filters with the dummy load connected in modules for each of the narrow-band inputs of the combiner. They are commonly used when the channels of the transmitters combined are closer or when there is a need for the broad-band input which enables adding of additional channels in the future by simply connecting new module to the broad-band input. 
When more than four transmitters have to be connected to the same antenna system combination of star-point and constant impedance type of combiner can be used. 
Since each system configuration is unique for every order engineers in ELTI perform detailed analysis before suggesting the best possible solution to the customer.
All the specifications of the combiners apply to the minimum channel spacing (1.8MHz for the star-point type and 800kHz to the CIF type).