PSK31 is gaining more popularity among amateur radio enthusiasts. It’s extremely small bandwidth and excellent performance in weak signal conditions make this mode perfect for low power HF stations. PSK31 is a digital transmission mode with just about 31 Hz bandwidth. The signal conveys data at a data rate of 31.25 baud and is extremely … [Read more…]
The current issue of ARRL’s magazine QST features an article about PSK31 on 2m in FM. This article is going to show why this is an unnecessary waste of bandwidth and therefore nonsense. PSK31 is a digital transmission mode designed for minimum bandwidth and great performance even in weak signal conditions. Sending a PSK31 signal … [Read more…]
STM’s STM32 F3 series of microcontrollers offer 32-bit performance with DSP functionality. To make the evaluation of this microcontroller easier, STMicroelectronics offers an evaluation board called the STM32F3DISCOVERY. If you have ever wanted to experiment with an RISC microcontroller that comes with special Digital Signal Processing (DSP) capability, the STM32F3DISCOVERY board might just be the … [Read more…]
Clock recovery in Spread Spectrum applications and BPSK modulated signals can be somewhat tricky. There are no commercial solutions available solely for this task either. Or are there? This article shows a great off-label use of the Abracon ABFT. Clock recovery in a Direct Sequence Spread Spectrum (DSSS) receiver can be quite a challenge. Because … [Read more…]
In March, 2012, Abracon announced the production of ultra-low jitter, VCXO based frequency translators / jitter attenuators. This is supposed to resolve some problems that accompany classic PLL-based designs at an affordable price. Now, the ABFT frequency translators / jitter attenuators are available on the market and it’s time to have a closer look. The … [Read more…]
This article is going to take a closer look at the properties of a pseudo random bit sequence and a simple direct sequence spread spectrum signal both in the time- and frequency domain using the FFT capabilities of a Teledyne LeCroy WaveAce 1002. A while back, I posted an article about a Pseudorandom Number Generator … [Read more…]
Jackson Labs offers several different precision timing solutions. Among them are various GPS-disciplined oscillators. They sent me an evaluation board for one of their ultra small, low-cost GPSDO. So let’s check it out! The GPS-disciplined Oscillator (GPSDO) reviewed in this article is a state-of-the-art eval board from Jackson labs equipped with a high-performance GPS receiver, … [Read more…]
Low-cost oscilloscope are a booming market. With the low-cost, entry level WaveAce series Teledyne LeCroy wants to get their piece of the big cake. This review is going to have a closer look at the Teledyne LeCroy WaveAce 1002. The WaveAce series oscilloscopes from Teledyne LeCroy are LeCroy’s answer to low-cost entry level oscilloscopes. They … [Read more…]