TX RX Systems RF Conditioning Products.

RF Critical Communication Infrastructure. For the most challenging frequency plans.

Since 1976 TX RX Systems has primarily targeted the US market, as the one-stop-supplier and reference standard for LMR application. TXRX has a large reference base and is a strategic supplier for customers like Motorola Solutions, Harris, state and various local- and federal markets in the U.S. In 2018 TXRX was acquired by Combilent A/S, as part of the Combilent Group.

TX RX Systems offers one of the widest ranges of RF products characterised by high modularity, customisation and integration and is now extending the Combilent Group product portfolio in the VHF, UHF, and 700/800/900 MHz bands.

TX RX Combilent Logo

Danish-based Combilent has since 2004 revolutionized the RF hardware industry, with unbeatable performance through innovation.
Radiocoms Systems Ltd
is proud to be their UK & Ireland Distribution Partner.

TX RX Cavity Filters

Examples of cavity filters.

Although a primary building block for duplexers, multicouplers and preselectors, these cavity filters can be used individually or cascaded together to prevent interference or system clean up.

TXRX cavity filter are available as bandpass, vari-notch and series notch filters, with Q-factor designs of 4”, 6”, 8” and 10”, for VHF and UHF solutions.

All types of RF filters may be cascaded to achieve an arithmetic sum of individual filter attenuation.

Up to 6 dB of additional attenuation can be achieved when the proper length of cable is used to interconnect the cavities.

Cavity Filter Loop Kits allow same cavity to be configured for different responses.

12 Channel 10 T-Pass-Combiner.

The combining systems allow multiple transmitters to share the same antenna, maximising tower utilisation, reducing tower loading and reducing interference risk.

Designs may be for a simple antenna system or a multiple antenna system with challenging frequency plans.

TX RX is known for highly specialised technical expertise in providing system designs for simple applications as well as the highly configured applications.

TX RX’s combining systems consist of a very broad offering in the VHF, UHF 700/800 and 900 MHz frequency bands.

TX RX 12Channel 10 T-Pass Combiner
TX RX Duplexer


The duplexer is used to allow a transmitter and receiver, operating on different frequencies, to share a common antenna while operating simultaneously. The filters that make up the duplexer isolate the transmitter from the receiver by doing two important functions – the most important is filtering out any transmitter noise sidebands that are being generated on the receive frequency. The second function is protecting the receiver from transmitter carrier overload. The amount of isolation necessary is dependent upon the TX to RX frequency spacing. As the frequencies get closer, a higher value of isolation is required.


The preselectors are primarily used to limit the bandwidth in front of a multiple-receiver system and post selectors are used to limit the bandwidth after a multiple-transmitter system.

The size and complexity of the RF Preselectors or Post Selectors range from a model built from three helically-loaded 1.3-inch rectangular resonators for relatively low-selectivity receive-only applications, where 2 dB of loss can be tolerated, to four 6.625-inch cavities that can handle 400 watts with high selectivity and loss of 1 dB or less.

TX RX offers a wide variety of standard and custom preselector and post selector filters to meet the requirements of the communication systems that have been and are being designed today.

TX RX Preselector
TX- RX Receiver Multicoupler

Receiver Multicoupler.

The broadband receiver multicouplers provide unequalled performance in a space-saving package, exhibiting a maximum noise figure of only 1.5 dB and minimum excess gain of 10 dB which for maximum sensitivity. All units are designed for ease of expansion, with models covering applications from 135-902 MHz. Combline preselectors are available for all common applications in the 700/800/900 MHz bands.

The integrated receiver multicouplers combine filtering, amplification and signal splitting into one compact unit. Each unit splits up to 8 frequencies and is easily expandable up to 32 ports.

The system includes LNA´s, 12V DC backup connections, a pre-tuned high selectivity bandpass preselector, a -30dB test port, and control and monitoring of gain via the front panel, Ethernet, and SNMP v2C interfaces. Alarms are generated on all interfaces and logged upon high internal temperature, high current in either amplification branch, out of range internal voltage, or communication errors.

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