Cardiff Microwave Roundtable
An SDR based Beacon Project
Third year students in Cardiff University’s Electronics Engineering program complete a course in which they design and build a project. This year two students chose to work on a 1.3 GHz beacon which the Cardiff University ARS hopes to install on campus. They’ll give a report on the progress and learning experience.
Designing a 1.3 GHz RF Power Amplifier
Shem is designing a 25 Watt, class AB amplifier using a Cree Gallium Nitride transistor. The design balances efficiency with linearity and gain.
A PI4 Beacon Modulator using SDR and GNU Radio
Ahmed has been implementing the PI4 beacon modulation protocol in Python and GNU Radio to be transmitted from an Analog Devices ADALM PLUTO SDR. Additionally a low power, band pass filter will supress any out of band spurious signals.
Cardiff RAYNET’s Mesh Network for Emergency Response
Dave Thomas MW0RUH
The Radio Amateur’s Emergency Network (RAYNET) organization in Cardiff has built a mesh network operating on the 2.4 GHz band. This provides a variety of communication and information services with no reliance on the Internet. Dave will talk about the network, services, and users.
Interlacing and HD for the DATV Express and LimeSDR
Do try this at home!
Phil Longhurst GW8BVI
Interlacing is a 1930’s technique which has a lot of benefits and is still in use today (1080i HD). But it is a pain to get it right and if you don’t the results look terrible! Using paid s/w (Vmix) and free s/w (OBS broadcaster) it can be done if you know how. 1080i HD looks fab and can be transmitted via a mere 1MS/s DVB-S2 with low-latency h.264 (not even the latest 4K HEVC) phys channel.
Tracking and Measuring Distances with LoRa at 2.4 GHz
Stuart Robinson GW7HPW
A brief introduction to using the Semtech 2.4 GHz LoRa devices for long distance high altitude balloon tracking and measurement of distance by time of flight of a packet exchange.
Transistor Load Lines at Home
The Current-Voltage load line of a transitor tells you lots of information about how it will perform in an amplifier, but often aren’t included in datasheets. Learn what these useful measurements mean and how to take them using simple equipment. This talk shows how load lines can be used in amplifier design, starting with the measurements of IV curves and ending with an overview of how they can be used in high efficiency PAs.