Standalone Versions of LMR SDR!

 I had posted about LMR SDR a couple of days back. LMR SDR covers from 160m to 10m band and gives an output of up to 50 mW which has to be amplified further using a linear amplifier, if needed. It is based on Arduino Nano microprocessor and Si5351 programmable clock generator. A computer and sound card are needed for the operation of the basic version of LMR SDR and uses PowerSDR software. Yesterday VU3GEX told me about standalone versions of LMR SDR which do not need a computer. He mentioned that ESP32 and STM32 can be used in Standalone LMR SDR. STM32 is a family of 32-bit microcontroller integrated circuits by STMicroelectronics. ESP32 is a series of low-cost, low-power microcontrollers. To my great surprise, a search for ESP32 Standalone LMR SDR brought me to RDvibes, a website by VU3ZOF, whom I have been hearing and talking to on 40m for the past few days. According to the website, the standalone variant was developed by YD1GSE and uses ESP32-A1S processor. The exciter front end design is similar the usual LMR SDR. So it is getting more and more interesting!



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