RPA-2 Modular RX Pre Amplifier

The RPA-2 is a low-noise, modular receive preamplifier for medium and short wave. This preamplifier helps to hear even the weakest signals without raising the noise unnecessarily. It is used for any kind of receiving antenna, be it long wire antennas, beverages, loops, broadband dipoles and many more.

The RPA-2 amplifies the received signal by about 16 dB, in the frequency range from 300 kHz to 35 MHz. A special "push/pull" amplifier design is used, which provides a superior dynamic range and a very good IMD3 value. At the same time additional distortion of the received signal is avoided.

An additional optional module can be installed in the RPA-2 receive preamplifier. There are two modules available: the Receiver Guard 5000HD module, which protects the input against overvoltage, and a transformer and impedance converter from 75 to 50 Ohm.
The Receiver Guard module is useful when transmitting from the same location at a short distance. In this way the receiver input is protected against overvoltage, even if there is a thunderstorm nearby. The 75 to 50 Ohm transformer module allows the use of low-cost and low-attenuation 75 Ohm cables for the receiver antennas, which are often installed at great distances.

The RPA-2 preamplifier is operated with 12 to 18 V DC. Here you should choose a quality supply voltage that is as clean as possible, preferably from a linear regulated power supply. The usual cheap switch mode power supplies quickly cancel out many of the advantages of the preamplifier such as its low noise. The voltage is supplied either via a separate connector (included in delivery) or via the coaxial cable. The BNC and F-connectors are deliberately chosen to avoid confusion with transmit signals (usually on PL or N connectors). The RPA-2 is supplied in a solid metal housing with screw tabs. A comparable preamplifier is available as a plug-in module for the NCC-2.

Frequency range: 0.3 - 35 MHz
Gain: typ. 16 dB
Noise figure: 3.5 dB
Dynamic range: >= 110 dB (500 kHz BW)
Connection: BNC + F
Voltage: 12 - 18 VDC
Current: 140 mA