Introduction; Features - DX Engineering RPA-2 Manual

Introduction

The DX Engineering DXE-RPA-2 Modular Receive Preamplifier is a high-performance broadband
LF through HF receiver preamplifier that features exceptional immunity to overload. It also has an
excellent noise figure and a low input SWR, optimized
for the 300 kHz to 35 MHz range. Meticulous
craftsmanship and durable, robust components allow this
50-ohm preamplifier to withstand high signal levels
while providing superior dynamic range and third-order
intercept performance that equals or exceeds most
receiver and transceiver front-ends. Unlike other external
preamplifiers and many transceiver internal
preamplifiers, the RPA-2 enhances the readability of
weak signals without artificially increasing the noise. On low bands and beyond, weak signals
become more intelligible using this preamplifier in conjunction with proper adjustment of the RF
Gain and Attenuator in the transceiver.
The RPA-2 is a combination of a redesigned aluminum shielded enclosure chassis with the DXE-
RPA-2-PM Receive Preamplifier Plug-in Module factory installed. The DXE-RPA-2-PM module
retains the essential characteristics of the milestone product, the original DX Engineering RPA-1.
Featuring one internal optional module slot, the RPA-2 allows the use of the optional DXE-IT-PM
75 to 50-ohm Impedance Transformer Plug-in Module or the optional DXE-RG5000HD-PM
Receiver Guard Plug-in Module or optional filter. See DX Engineering Receive Filters.
While many other common preamplifiers suffer from harmonic distortion, the DXE-RPA-2 low-
noise preamplifier features an advanced push-pull design that eliminates harmonic distortion. High
quiescent current increases its ability to handle strong signals without distortion or overload. This
high performance device must be powered with a well filtered and regulated DC power supply and
offers maximum performance at +13.8 Vdc to +18 Vdc input. Never use an inexpensive, poorly
performing wall transformer to power this top-of-the-line preamplifier.

Features

 Internal circuit impedance of 50-ohms for direct connection to 50-ohm receive systems and
antenna feedline BNC connectors with no transformer required
 Internal slot accommodates the optional 75 to 50-ohm Impedance Transformer Module to
accomplish transition from a typical F connector 75-ohm receive antenna feedline to 50-ohm
equipment, without losses
 Input and output connectors BNC and F types, prevent accidental connection to transmitting
devices
 Automatic RF bypass relay also turns the preamp off when the dc power is removed
 Green LED indicates when DC power is present and the preamplifier circuit is engaged
 An ingenious positive-capture threaded-sleeve 2.1 mm power connector that ensures the DC
power cannot be accidently disconnected from the RPA-2
 A simple internal jumper allows the RPA-2 to be powered by DC on the feedline for use on
antenna types that require a preamplifier at the antenna such as Pennants, Flags or K9AY Loops
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