This project is about MC3362 and ADF4351 based modularized, 2-meter narrow band FM receiver. In this design, the receiver splits into three modules as RF preamplifier, MC3362 tuner, and ADF4351 oscillator. The RF preamplifier builts around BF900 dual-gate MOSFET. The tuner stage builts using the popular MC3362, low power narrowband…

This project is about a wireless musical call bell, which I designed to meet some of my friend’s requirements. This circuit design uses only the 4000 series CMOS logical ICs, NE555, UM66, and TDA7233 audio amplifier IC. For the remote control, we use a 433MHz 4-channel remote control module. …

IR Clone is an open-source IR remote control analyzer tool. This utility can analyze any IR remote control that modulates the IR signal with a 38kHz carrier signal. This utility has an option to store and retrieve up to 16 IR signals. …

Recently we looked for a replacement class-D power amplifier to replace my old TDA2030 power amplifier build. While searching for a suitable power amplifier IC, we found TPA3001D1 from the local market. This IC is a slightly older 20W Class-D power amplifier manufactured by Texas Instruments. At the time of…

In this project, we built an STM8S005C6T6 based Ethernet development board for our IoT experiments. This development board consists of ENC28J60, 10BASE-T stand-alone Ethernet controller, CH340G, USB serial interface, 2 LED indicators, and passive buzzer unit. The firmware framework for this development board has been developed using SDCC. To enable…

This project introduces a digitally controlled 5.1 channel audio preamplifier system. This amplifier is specifically designed to increase the gain of the multi-channel PC sound cards. The main reason for building this amplifier is the limited gain received from the sound card with the Creative Inspire T6300, 5.1 surround speaker…

In this project, we extend the shortwave superheterodyne receiver we developed a few years ago. Like the previous design, this receiver operates on the traditional superheterodyne principle. In this upgrade, we enhanced the local oscillator with Si5351 clock generator module and Arduino control circuit. Compared to the old design, this…

This active subwoofer filter system provides the frequencies required to run the subwoofer within its limits. The purpose of this unit is to prevent the subwoofer speaker or circuit from overloading at unsupported frequencies. This approach can ensure the safety of the subwoofer speaker or driver circuit. This system consists…

The QN8035 is a stereo FM radio receiver launched by the Quintic Corporation. Compared to other popular digital FM tuners (RDA5807, TEA5767, etc.), this tuner does not seem to be as popular among the DIY community. As we have seen, the biggest problem with this IC is the lack of…