


Operate up to 4 TETRA radios through a single antenna
The TETRA Antenna Combiner works in conjunction with the Gemini survey tool to allow up to 4 TETRA class 3 (3W) radio terminals to be connected to a single antenna whilst meeting all ETSI requirements for intermodulation products. The Combiner includes an ultra-linear wide-band TETRA amplifier to compensate for combining losses as well as specially designed receiver amplifiers to eliminate wide-band noise interference between terminals, thereby ensuring that there is absolutely no reduction in performance for any radio terminal.
Two models are available:
Model A – Up to two class 3 radio terminals may be configured for 0dB gain whilst the other two radio terminals must operate with 11dB loss.
Model B – Up to two class 3 radio terminals may be configured for 0dB gain whilst the other two radio terminals must operate with 11dB loss.
Terminals with 11dB loss simulate the performance of a hand-portable antenna and further attenuation of 5dB or 15dB may be added to simulate building losses. The combiner also includes a switch to insert a further 5dB attenuation into the transmit path to simulate the transmit power of a class 4 (1W) hand-portable.

- Reduces network survey time by operating up to 4 different radio terminals simultaneously
- Inherently adaptable allowing many different configurations
- Single antenna ensures that all radio terminals have the ideal radiation pattern
- Provides high levels of isolation between terminals with no degradation of signal
Frequency: Tx 380-385MHz
Rx 390-395MHz
Tx Insertion Loss: Model A: Ports 1 & 2: 0dB
Ports 3 & 4: 11dB
Model B: All Ports: 11dB
Rx Gain: Configured to be identical to Tx path loss for each port
Port to Port Isolation (Tx Band): >60dB
Port to Port Isolation (Rx Band): >65dB
Antenna to Port Isolation (Tx Band): >60dB
Intermod products: < -36dBm in transmit band
< -110dBm in receive band
LNA noise figure: 3dB at 2dB gain
VSWR: 1.5:1
Connectors: BNC
Power Supply: 12V @ 15A (Model A)
12V @ 1A (Model B)
Dimensions: 6u 19” rack (266mm x 483mm x 470mm)