QRO.cz RX Preamp Module Boxes

QRO.cz RX Preamp Module Boxes, featuring the 2N5109 transistor, are based on the proven W7IUV design and are ideal for use with receive-only antennas such as beverages, Double Half Delta Loops, flags, and other popular RX antenna designs. The Preamp Box offers up to 18dB of gain, with a built-in variable attenuator that allows you to easily adjust the gain to your desired level. A multi-turn potentiometer lets you fine-tune the transistor bias for optimal performance. The unit includes two relays that automatically switch to bypass mode when no power is supplied. Power can be provided either through a direct external DC connection or via a bias tee for power over coax.

Key Features

• High Dynamic Range: Delivers up to 18dB gain with a real IP3 of 37 dBm, ensuring excellent linearity and signal clarity.

• Flexible Power Options: Operates from 12–15VDC via direct external DC connection or bias tee, with automatic bypass relays when unpowered.

• User-Adjustable Gain & Bias: Multi-turn potentiometers allow precise control of gain and transistor bias for optimal performance.

Specifications:

• Frequency Range: Broadband, 0.1 z to 30MHz

• Gain: Adjustable from 0 to 18 dB

• Impedance: 50-Ohm

• IP3 Rating: 37dBm at 18VDC / 90mA

• Output Power: Up to 26dBm

• Power Supply: 12–15VDC (direct or via coax)

• Current Draw: Up to 180mA (including relays)

• RF Connectors: UHF female SO-239

• Protection: Front-end diode protection (jumper-selectable)

• Bypass: Dual-relay automatic bypass when unpowered

• Assembly: Fully assembled and tested SMD version

• Enclosure: IP56-rated

• Dimensions: 3.94 x 3.94 x 1.97in. (100 x 100 x 50mm)

• Weight: 0.75lbs. (0.34kg)