The idea of developing a universal ADTRX_UR4QBP_V2 board came to me immediately when I decided to try connecting my ACER TravelMate 2410 laptop to the ADTRX_UR4QBP board. Reception worked fine on the built-in AC`97 sound card, RX/TX switching worked via a USB-COM adapter, but I still couldn’t get it to transmit… As you know, most, and I would say all, laptops have sound cards with combined linear and microphone inputs in one connector. I decided to add another signal relay with two groups of contacts to the circuit to switch the sound card input either to the NE5532P op amp output in reception mode or to the microphone in transmission mode. The board works with the KGKSDR program. The circuit diagram of the board Fig. 1 has practically not changed compared to the ADTRX_UR4QBP board, I only ad
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Keeping up with the times, it was decided to continue the theme of controlling tube power amplifiers. The use of a color 3.2-inch graphic display, as well as a powerful 32-bit microcontroller on the ARM Cortex-M3 core allows expanding the capabilities of the new control board.
