Introduction In the previous post (Ref.1) I examined the signal flow through the RPiZonia Zero IF Direct Conversion Receiver by examining the Block & Level testing diagram. Figure 1 shows the schematic diagram. Figure 2 shows the Block & Level testing diagram. Reception SW Station 11.930MHz In order to receive a shortwave station on 11.930MHz,… Continue reading HF Receiver Testing – Zero IF Direct Conversion_b
HF Receiver Testing – Zero IF Direct Conversion_a
Introduction Several years ago I developed a Zero IF Direct Conversion HF receiver (Ref.1) to be used as a lab component of my HF Telecommunications course (Ref.2). The idea was to learn HF theory by Scicos simulation, electronic circuit design (schematic capture, pcb design, LTspice simulation, working with smd) and testing with a scope and… Continue reading HF Receiver Testing – Zero IF Direct Conversion_a
OpenPlotter – RPi4 Headless_b
Introduction Previously I looked at using the RPi4 remotely with a WiFi hotspot and controlled by an iPhone10 using VNC viewer (Ref.1/2). In this post I field tested the setup down at Toronto Harbourfront. Figure 1 shows the setup. Field Test Figure 2 shows the field equipment setup on a bicycle. I was not able… Continue reading OpenPlotter – RPi4 Headless_b
OpenPlotter – RPi4 – USBpwr
Previously all my work on OpenPlotter was done on an RPi3B+ installed in a PI-TOP3 development Laptop that featured a screen, keyboard, and proto board connected to the GPIO (Ref.1-Ref.10). I started with the basic installation, OpenCPN with GPS, OpenCPN with GPS & AIS, Marine Weather on GQRX, Sensors for Temp/Pres/Pitch/Heel/Compass Bearing and GRIB weather… Continue reading OpenPlotter – RPi4 – USBpwr
RTL-SDR – V1/2/3 – USBpwr
Introduction In many applications, where ac power is not available, equipment must be operated off battery/solar systems. In these case, knowing your power requirements are critical. Recently, small inline USB power meters have become available and they can give you an immediate answer to this question (Ref.1). RTL-SDR – V1/2/3 Power Measurements I did a… Continue reading RTL-SDR – V1/2/3 – USBpwr