Category: Telecommunications

Introduction In the previous two posts I tested a 433MHz LNA for its frequency response or S21. I first used a PlutoSDR signal generator and then a NanoVNA (Ref.1/2). In this post I will add a BPF Band Pass Filter and examine the response of the BPF+LNA using the NanoVNA. Measurement Setup Figure 1 shows… Continue reading NanoVNA for 433MHz/70cm BPF+LNA Testing

Introduction In the previous post I tested a 433MHz LNA with a PlutoSDR as a signal generator and determined it had a wideband response over 100MHz – 800MHz with a gain of approx. 23dB. In this post I will do the same measurement but this time with a NanoVNA. I am always looking for an… Continue reading NanoVNA for 433MHz/70cm LNA Testing

Introduction I want to do some experiments in the amateur radio 433MHz/70cm band. So I was looking for an LNA/BPF as I used in previous experiments. I found two units on line, one in a metal case and one on an open PCB. The PCB unit arrived first, so I tested it using white noise.… Continue reading PlutoSDR for 433MHz/70cm LNA Testing on GNURadio

Introduction In previous posts I looked at programming the Si5351A clock generator for IQ quadrature and for simple single frequency output using Arduino (Ref.1/4). When used with amateur radio receivers and transmitters, we have to keep in mind that we are not dealing with a sinusoidal source but a square wave. From Fourier theory, a… Continue reading Si5351 Clock Generator Spectrum on GNURadio