Back in 2018 we posted about Igor Yatsevich's Easy-SDR project which consisted of open source designs for a Mini-Whip antenna and upconverter. Igor has now added several new open source designs to the project including a bias tee, LNA, LNA with filtering, attenuator and SPDT antenna switch. On his Reddit post he notes:
The most interesting thing I've added so far:
- Most of the devices are now prepared for installation in a metal case measuring 80 x 50 x 20 millimeters.
- Completely redesigned LNA design. Now, Bias Tee powered amplifiers are housed in a 50 x 25 x 25mm metal case and have N-type connectors.
- Added an amplifier based on the PGA-103 microcircuit.
- Added the ability to install filters in final amplifiers (a separate printed circuit board, depending on the filter used).
- Added a new device - SPDT antenna switch for receiving antennas.
- The UP converter has been redesigned. Added intermediate buffer stage between crystal generator and mixer.
- RF lines in all devices were recalculated to correspond to the characteristic wave impedance of 50 Ohm.
- Reduced size of PI attenuator PCB.
In this project, I focused on the simplicity of self-assembly devices, which you can make at home. In the repository, you can find detailed assembly instructions, a list of necessary components for assembly, and GERBER files.