A very well attended Sunday FreeDV net on 7045 this morning from 10:30 eastern time. Stations on frequency were: VK2AWJ, VK2BX, VK2UMZ, VK3BAL, VK3CDH, VK3DJB, VK3FC, VK3GTP, VK3ID, VK3KEZ, VK3PCC, VK3PTR, VK3SRC, VK5ABE, VK5AG, VK5KHZ, VK5KVA, VK5MH, VK7DMH, VK2KO, VK2KNC, VK2YW, VK2CJB and me VK3TPM. 24 stations!
While working on my C port of FreeDV RADE1 I wanted a reliable radio signal to test with. While I have off air recordings from the FreeDV GUI app I thought it would be nice to generate my own files to transmit with the HackRF Portapack Mayhem which can record to C16 files and play them back. There's a TXT file with each recording that specifies the sample rate and output frequency.
I've made a python utility that can read a WAV file recording and produce C16 sideband. Here's how it sounds.
The code is pretty short so I've published it as a gist on GitHub.
The HackRF is a wonderful tool for radio experimentation. I'm using the standalone Mayhem but it works just as well from a computer via USB with hackrf_transfer.
An excellent FreeDV RADE1 net here in South East Australia with 23 stations on frequency. Some for the first time. Stations: VK5KHZ, VK5KFG, VK5AG, VK3ZUM, VK5KVA, VK3UBK, VK3SRC, VK3KEZ, VK3JCO, VK3GTP, VK3FC, VK3DJB, VK3CDH, VK3BQO, VK3BAL, VK2YW, VK2XOR, VK2UMZ, VK2KNC, VK2DWG, VK2AWJ, VK5HM and me VK3TPM.
Normally I call in stations in alphabetical order but today I thought I'd trick Jack VK5KVA, by going in reverse.
Today marked a milestone in my investigation into using Claude Code with a complex codebase. I had a FreeDV RADE contact with another station using code it wrote under my instruction in just one week - very much part time. Here's a receive demo:
My thanks as always to Joe, VK3SRC, for assistance in testing and feedback. Also thanks to Britt, VK3AOB who responded to my first call which I really expected to not be decodable.
Here's how Claude Code looks while working on a bug in the code (click to enlarge):
The code is here: https://github.com/peterbmarks/radae_decoder As you can see the name of the project is no longer correct as it encodes as well.
Tech Talk takes a look at this and how the big four tech companies are faring after they've spent big on AI.
Peter Marks, mobile software developer and technology commentator from Access Informatics, joined Philip Clark and listeners to Nightlife with the latest tech news. Listen here: https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106328266
An excellent Sunday FreeDV net this morning with VK2, VK3 and VK5 stations all with good SNRs.
Some interest was expressed in the C port of the RADAE python code which is encouraging. On the frequency, (not everyone transmitted), VK2AMF, VK2AWJ, VK2DWG, VK2GMH, VK2YE, VK3DJB, VK3FC, VK3GTP, VK3JCO, VK3KEZ, VK3XCI, VK3YV, VK3ZUM, VK4TEW, VK5ABE, VK5KHZ, VK5KVA, VK5LN, VK5ST, VK6YR, VK3BAL (running three copies of FreeDV!), VK3AOB, and me VK3TPM.
One of the objectives of the work on RADEV2 is to replace the currently required Python runtime from the distributed FreeDV app. This would make it easier to install, smaller, and hopefully more efficient. (Other objectives are improvements in how it works). Python is an important part of the project and is used for prototyping and testing - that won't change.
Re-writing all the python in C is a daunting, tedious, expert task, estimated to take many months that would result in an app that works pretty much the same as it does today.
I've been experimenting with Anthropic's Claude Code recently and it occurred to me that one of the things LLMs are particularly good at is translating between languages, human or programming. The result of just a few days of guiding Claude Code is an experimental RADEV1 decoder app.
The intial work, which includes command line tools to decode and encode from and to WAV files is on github here.
The proof of concept Linux application shown above is in a Github repo here.
While it seems to work and does pass important tests, this is not code supported by the project at this time.
Claude Code enabled me to attempt something I wouldn't dream of until now. It was quite a big job for it (I hit my quota on two separate days and had to wait to resume).
Working with an LLM to write software does still require enough knowledge to know what to ask for and to guide the work.
I hope this work will encourage others to develop innovative FreeDV RADE software along side the official FreeDV App which remains the reference release. My sincere thanks to Dr David Rowe for his fantastic work and his help and encouragement with this little experiment.
Many years ago I handed down a MacBook air to our youngest daughter. She used it until I handed down a later machine. Last week she returned it and I'm amazed to see how heavily she had used it over the years without complaint.
It still works although the battery is dead now.
Some people complain that Apple is expensive but I think it's value for money.
This kind of keyboard wear reminds me of an HP25C calculator I had many years ago. It was also a piece of quality engineering and, as I recall, one feature was that the symbol on the buttons was plastic that extended right through the key so it would never wear off.
