Dilshan R Jayakody’s Web Log

The BG7TBL FA-5 frequency counter has become recognized as an excellent choice for experimenters and radio enthusiasts, offering high-spec performance comparable to branded units. But it remains remarkably accessible due to its low cost.  FA-5 Frequency counter. The FA-5 has powerful hardware. However, most existing control applications lack a good user experience. Many of them rely on scripting languages, such as Python, while others utilise simple command-line interfaces . These limitations inspired us to create FA-5 VizControl . This native application provides a comprehensive, intuitive, and portable desktop experience for managing the FA-5 . We developed FA-5 VizControl using Lazarus and the FPC ( Free Pascal Compiler ). This choice ensures maximum compatibility and portability. The application functions as a standalone, portable executable on both Linux and Windows operating systems. There is no need for complex installation routines. Users simply download and launch...

This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is designed to work around 9V to 12V DC power source. Both 2SC930 transistors can replace with any high-speed NPN transistor such as 2SC829, 2SC933, etc. Testing 5030kHz FT-243 crystal using a prototype version of crystal tester. In our lab, we use Manhattan-style layout to prototype this crystal tester and it produces highly accurate results with an above-specified frequency range. According to our observations, after 27MHz, the amplitude of the waveform starts to decrease steeply. Schematic and Stripboard wiring layout for this crystal tester is available to download in here .