TRC Series Controllers

The TRC Series, available in five standard designs, are durable PLC-driven switch controllers. 

• TRC-1: single switch, two transmitters, one antenna, dummy load

• TRC-1P: same as TRC-1 with added plate on/off function

• TRC-2: two switches, two or three transmitters, two antennas, dummy load

• TRC-2A: same features as TRC-2 with modified switch and antenna arrangement 

• TRC-3: three switches, one antenna, two or three transmitters, combiner/injector

TRC Series Design

A  Tunwall Radio switch controller provides protection for transmitters and coax switches. Without an active switch and transmitter controller, operator error can easily result in burned-out switches and off-air time. Our controllers use a timed sequence to remove RF power, move the switch(es), and verify switch positions before RF power is restored. The controller’s automatic load interlock allows easy load testing with load protection – the controller will not allow the off-air transmitter to operate unless the load's air or water is running. 

Our controllers will save you time because there is no need for you to program anything. The pre-programmed PLC (programmable logic controller) in the TRC controller provides control and logic for the coaxial switch and transmitters. The PLCs we use have proven to be extremely reliable. They are designed to withstand typical challenges to electronic equipment in industrial environments; heat, dust vibration, magnetic fields and power line transients.

No rewiring coaxial switch cables if your switch position 2 is “normal” – TRC controllers easily reverse switch logic and control, individually for multi-switch systems.

Controllers are not useful if no one can figure out how they work. The TRC series unique front panel flow chart graphic with switch position indicators displays the RF signal path and load status.

TRC Series controllers are built in aluminum rack mount boxes with engraved front and rear panels. There are no screens to navigate through, and nothing to program. 

Front panel pushbuttons make operation simple. 

The key switch operated local mode prevents remote commands during maintenance. The key switch operated auto transfer function can change transmitters automatically upon main failure. 

Unlike most other controllers, Tunwall Radio controllers are compatible with all standard coaxial switches. The TRC-1, 1P, 2 and 2A can also be used with RF contactors for non-directional AM stations. Optional controller-to-switch cables can be made to your desired length for any switch type.

The coaxial switch(es) plug into 9-pin AMP connector(s) on the rear of the controller.  Transmitter and remote control connections are made to barrier strip terminals.

Our five standard models in the TRC Series are detailed below. 

Custom controllers are also available, for details please see our custom controllers page  or contact us for a quote. 

TRC-1 and TRC-1P

We offer two single switch controllers: The TRC-1 and the TRC-1P. Both are FM or AM non-directional controllers, designed for one coax switch or 120V AM contactor, two transmitters, one antenna and a dummy load. Both feature a key switch selected auto function which will transfer to the aux transmitter upon failure of the main transmitter. Each also has a dummy load ready light, it works with the load interlock logic for automatic load protection.

The TRC-1P controller has one added feature: plate on/plate off functions for both transmitters.

Front panel designs are the same for both units. The TRC-1P has a rear indicator light for the plate on function.

Drawings of both units, and a drawing highlighting the differences between the 1 and 1P are available below.

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TRC-2
The TRC-2 controller is an FM or non-directional AM controller. It is designed for two coax switches or 120V AM contactors, two or three transmitters and two antennas. The key switch selected auto function will transfer to the aux transmitter upon failure of the main transmitter. The dummy load ready light works with the load interlock logic for automatic load protection.

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TRC-2A
The TRC-2A controller offers the same features as the TRC-2, but with a different switch and antenna arrangement. The TRC-2A can also be used by AM non-directional stations with an aux antenna.

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TRC-3
The TRC-3, our three switch controller, is for combined FM transmitter systems. It is designed for three coax switches, one antenna and a combiner/injector. Logic for a third transmitter is programmed on this controller. The key switch selected auto function will transfer to separate transmitter 1 or 2 mode if either fails. The dummy load ready light works with the load interlock logic for automatic load protection.

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