A Front End Limiter is a passive device that protects a receiver from an excessive signal preventing that excess RF can damage it. It is important to keep this concept in mind, since the mission of an FEL is to protect a receiver from strong and excessive signals. Obviously, it must be installed between the antenna and the receiver. For example, when we have a receiver or SDR and in the around area we also have a transmitter, depending on the distance between the TX and RX antenna of the receiver and the power used, we must protect the receiver.

We have two models of equipment that include this FEL functionality depending on the use:

  • RX-FEL: Includes an FEL with input and output connectors (SO239, RCA or BNC). It is a model for only receivers and cannot be transmitted by it.
  • TRX-FEL: Includes an FEL with input and output connectors (SO239) but it differs from the previous one in that by means of relays you can make a bypass of the FEL. For this it has a power input and PTT signal input. In this way, if the PTT is connected to the tranceptor, when it passes to TX, the TRX-FEL is in bypass mode and can be transmitted without damaging the FEL.
  • Device that could be used on receivers, CANNOT BE TRANSMITTED THROUGH IT.
  • Connectors SO-239, as an option RCA or BNC
  • The FEL shows a impedance of 50 ohms and a SWR < 1.06 (1,8-30Mhz)
  • Insertion Lost < 0,43dB
RX View
  • Equipment that can be used with both receivers and transceivers.
  • It includes PTT to allow a bypass of the FEL circuit to prevent damage.
  • SO-239 connectors.
  • Specifications with the FEL active by default (PTT not activated)
    • Insertion losses better than 0.4dB in HF (0.5Mhz – 30Mhz)
    • SWR < 1.1: 1 in HF (0.5Mhz – 30Mhz)
  • Specifications with the FEL in By-Pass (PTT driven)
    • Insertion losses better than 0.04dB in HF (0.5Mhz – 30Mhz)
    • SWR < 1.05: 1 in HF (0.5Mhz – 30Mhz)
    • Supports 150W
TRX View
Technical characteristics common to all models
FEL – Insertion Lost
Make your order
Visit our Shop

    The TRX-FEL (Transceiver Front End Limiter) is a RF protector and limiter for your radio transceiver. Installed between the antenna or amplifier and the transceiver, it requires to be connected the PTT signal from the radio. By default (reception) it will limited any RF signal and will avoid to damage the receiver in the proximity to other transmitters. When the PTT is activated by the radio, the Front End Limiter will be by-passed.

    This model is highly recommended in multi operator contesting, SO2R or Field Day. 

    Specifications in RX (FrontEnd activated)

    • Insertion lost better than 0.4dB in HF (1.8Mhz - 50Mhz) 
    • VSWR < 1.06:1 Range 1.8-29Mhz

    Specifications in TX or ByPass (FrontEnd disabled)

    • Insertion lost better than 0.04dB in HF (1.8Mhz - 50Mhz) 
    • VSWR < 1.05:1 Range 1.8-29Mhz
    • Max power 150W
    47,00 VAT not included Add to cart
  • RX-FEL

    The RX-FEL is a RF protector and limiter for your radio receiver or SDR. Installed between the RX antenna and the receiver, it will limited any RF signal and will avoid to damage the receiver because strong signals.

    The RX-FEL is a device that will protect the receiver front end from high level signals when operating in the proximity to other transmitters which could damage it. Situations such as multi op contesting, SO2R or Field Day. 

    • Insertion lost better than 0.4dB in HF (1.8Mhz - 50Mhz) 
    • VSWR < 1.06:1 (reception)
    45,00 VAT not included Select options

Due to an excess in the current workload, delivery times can be extended up to 2 weeks.


Debido a un exceso en la actual carga de trabajo, los plazos de entrega se pueden alargar hasta 2 semanas.

This will close in 8 seconds