RX small preamp with 2SC5551

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This is very simply low noise preamplifier module with 2SC5551 transistor based on W7IUV design. You can use it as high IP preamplifier for RX antennas, buffer amplifier or small driver. Gain is up to 18dB and there is also built in variable ATT. You can easy set gain as high as you need! Amplifier has got low noise - lower than 2 dB up to 50 MHz and around 2,2 dB at 150 MHz. As well you can set right transistor bias with multi turn potentiometer. Two relays offer bypass switching if there is no power supply.

Main functions:



The measured values

Gain 10dB 0,5MHz to 50MHz

Gain 15dB 0,5MHz to 50MHz

Gain 18dB 0,5MHz to 50MHz

Bypass 0,5MHz to 50MHz

Available also in enclosure (KIT/assembled):


RF adapters


RX small preamp ver 1.1
Schematic and board pic sch brd
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Attribution-NonCommercial 2.0 Generic