Electronics

Universal Clock Translator using Renesas VersaClock 6E Devices

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Programming Kit for VersaClock 6E devices, such as the 5P49V6965 and 5P49V6975

Due to the popularity of the QO-100 geostationary amateur radio communication satellite, precision GPS reference frequency sources (GPSDO) are becoming more and more common in home labs. The desire to derive different, fixed frequency signals from a GPSDO has similarly been increasing as different devices requiere different reference clocks with different frequencies. Therefore, this article is taking a closer look at the VersaClock 6E devices from Renesas.

Program uBlox GPS-module timepulse frequency (dynamically) with an Arduino

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uBlox NEO-6 GPS module connected to an Arduino Uno for dynamic Timepulse 5 setting.

The uBlox GPS-modules are capable of providing various reference clock signals through the TIMEPULSE pin. By default, this pin outputs a 1 pulse-per-second (PPS) signal. For an upcoming project, a GPS disciplined oscillator (GPSDO), this output had to be adjusted to 100 kHz. Instead of using the manufactuer’s software, u-center, this task is supposed to be accomplished using an Arduino. This article shows how to (dynamically) adjust the TIMEPULSE reference signal using an Arduino.

JFET-based infinite impedance detector for AM-demodulation

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JFET-based infinite impedance detector for AM demodulation using a BF256B

The so-called “infinite impedance detector” is a circuit that was commonly used in the old days of vacuum tubes. Since vacuum tubes can be somewhat considered to be heated JFETs, it is evident that such a circuit can also be built using a more modern, silicon-based approach. This article covers my first experiments with a BF256B based infinite impedance detector.

Total Harmonic Distortion (THD) from dBc

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This article supplements to my article titled THD Measurement with an Oscilloscope and FFT, which appeared in Elektormagazine. Here I will explain how the formula to calculate THD-F from relative power values (in dBc) was derrived from the standard voltage-ratio formula. A more in-depth explanation of the entire subject can be found in my research paper titled Total Harmonic Distortion (THD) analysis utilizing the FFT capabilities of modern digital storage oscilloscopes.

Generate a stereo-FM multiplex waveform with Python and AWG

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Time domain view of generated MPX signal

Generating more complex arbitrary waveform files for modern test equipment doesn’t have to be difficult. For a recent project, I needed a stereo-FM multiplex (MPX) signal containing two different tones in the left and right stereo audio channels. This article is going to show how to generate such a MPX signal for Siglent SGD-series arbitrary waveform generators with Python and PyVISA.

SITOR-B / NAVTEX Test Signal Generation

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The NAVTEX test signal was successfully received on a NAV4 Navtex receiver

This article shows how to generate valid NAVTEX message bitstream using an Arduino. The Arduino implements proper CCIR476 character encoding, SITOR-B forward error correction, synchronization and phasing signals. An entry-level function generator is then used as a FSK modulator on 518 kHz where it can be received by a NAVTEX receiver.