I’m just staring to build a T41 SDR QRP Transceiver

SDR = Software Defined Radio, 
QRP is the Q code for reduce power, QRP radios are meant for low power operations.

Not sure if you want to go down the kit route but it will teach you an bit about RF theory and practical electronics.

There is also a good book about the kit, the theory, programming the Tensy (the microcontroller heart of the t41), etc.

4sqrp.com/T41main.php

www.amazon.com/…/B09WYP1ST8