Aspitech E-waste Recycling Tour

Yesterday Robert Hart was kind enough to take a group of local hackerspace members on a tour through Aspitech, and Adelaide e-waste recycler. The Australian government has mandated that all importers must pay to recycle 33% of their products (by weight), which has created a new, high growth industry. The South Australian government is . . . → Read More: Aspitech E-waste Recycling Tour

Not Activiating Mt Remarkable

Last Saturday I had my first Summits on The Air (SOTA) attempt on top of Mount Remarkable here in South Australia.

As a first step on Friday I registered my SOTA attempt on the Sotawatch web site

On Saturday morning I started by testing my FT-817 and Alexloop magnetic loop antenna at our camp. While . . . → Read More: Not Activiating Mt Remarkable

Fox Hunting

This weekend I have been attending the SERG Ham radio convention in Mount Gambier where I have enjoyed the company of some good friends and learnt a lot about fox hunting.

A group of us decided to go 3 weeks ago. The well-connected Mark VK5QI has been scouring Adelaide for fox hunting equipment, including beam mounts, . . . → Read More: Fox Hunting

FreeDV Robustness Part 3

Since the last post I have explored some improvements to PAPR, and tested the 1600/2000 modes introduced in the last post in real time. These tests have given me a little more insight into the problems with HF channels and led me to better understand the requirements. This has lead to a new 1600 bit/s . . . → Read More: FreeDV Robustness Part 3

FreeDV Robustness Part 2

Since the last post I have been working on two new FreeDV modes (1600 and 2000 bit/s), designed to improve the performance of FreeDV over HF multipath fading channels. This involved modifying the Octave and C modem code to support a variable number of carriers, a new 1600 bit/s Codec 2 mode, and some C . . . → Read More: FreeDV Robustness Part 2

FreeDV Robustness Part 1

Here is the next installment in my adventure of making FreeDV work as least as well as analog SSB over HF multipath fading channels. I’ve included the command lines I am using for those who want to play along with me.

Incremental Improvements

Over the past few weeks I have made some incremental improvements:

Bill Cowley pointed out . . . → Read More: FreeDV Robustness Part 1

Dead DC-DC converter in my EV

About a week ago I returned from LCA 2013 after being away from home for 1 month. My EV was parked at a house close to the airport. It burst into life and off I went. However about 1 km from home the front lights and dash went dim and the EV ground to . . . → Read More: Dead DC-DC converter in my EV

HF Modem Bit Error Patterns

I am working on improving the performance of FreeDV on HF channels. As a first step I have been exploring the bit error patterns from the modem using some samples of a 1300 km HF radio path. These samples were kindly collected by Mark, VK5QI and Brenton, VK2MEV.

The FDMDV modem has 14 DQPSK data . . . → Read More: HF Modem Bit Error Patterns (LCA) 2013

Last week I attended 2013, my sixth LCA. It was a very well organised and enjoyable conference for me. After a few days back I miss it. I have made some good friends at LCA over the years, and catching up with them is as important for me as the conference talks. It . . . → Read More: (LCA) 2013

Coherent PSK Demodulation on HF

This post is rather technical, and assumes a knowledge of PSK demodulator design. I apologise if it is difficult to understand for the general reader. I have spent the last few weeks working on this part time so felt compelled to record the results somewhere. Thanks to Bill Cowley VK5DSP and Peter Martinez G3PLX . . . → Read More: Coherent PSK Demodulation on HF