Simple JTTY app for Linux

Stephen, VK2BLQ, and I have been playing with the new keyboard chat mode that's in the next release of WSJT-X. It seems to work very well but the user interface there is a bit daunting.

It occurs to me that it could be as simple to use as one of the phone instant messenger apps and so, with most of the work done by claude, I created JttyChat that you see on the right here.

Very simple. Choose Settings under File and configure audio to and from your transceiver and the hamlib configuration to control transmit.

There's a Frequency menu with the list of suggested upper sideband frequencies taken from WSJT-X.

We've been chatting in the middle of the day between Melbourne and Sydney without any trouble. I've also had reports from Michael VK2TMC.

The Linux app is packaged up as an AppImage. You download it, uncompress, set properties to make it executable, and it should just work. Because I'm using QT6 the AppImage file is rather large as it bundles all the dependencies including hamlib.

Download here.

Tech Talk on ABC Radio - what computer skills do we need in the future

What does it mean these days to say someone is 'good with computers'? It used to mean you knew your way around different programs, as well has knowing where to find things. 

AI is changing all of that with being 'user friendly' the whole AI schtick! 

Philip Clark is joined by Peter Marks, software developer and technology commentator from Access Informatics, with a look at what skills we will now need into the future. 

https://www.abc.net.au/listen/programs/nightlife/what-computer-skills-do-we-need-for-our-future/107235742

JTTY - new mode for keyboard short message chat on HF

There's an interesting new mode coming in WSJT-X 3.2 that support short text messages over HF with the weak-signal performance of FT8 but without the need for time synchronisation. 

At the time of writing it's not quite out yet but it's in the release candidate of WSJT-X 3.2 so it won't be long.

Stephen, VK2BLQ, drew my attention to it and we had a chat between Melbourne and Sydney (714km {for Americans, sorry, I don't know how many football fields that is}).

We both reduced power to 1W and were able to talk without any problem.

Leaving it running on 40m I can see quite a bit of activity (click the image at left to see more).

It's great to have modes that work without the need for second accurate time synchronisation as this open the door to portable operation without internet.

Recently I've also been playing with RattleGram which is a similar idea of short messages over radio. There are apps for Android and iOS. It seems to be mostly used on VHF/UHF FM radios and probably isn't ideal for HF conditions.

I do miss the days of PSK31 when I used to have fascinating long form text contacts.

Phase nulling direction finder for fox hunting

Our club is holding a fox hunt in a few months. We have a few portable UHF beam antennas but I thought I'd try a simple design that uses the phase difference between two sense antennas. It's called a HANDI-Finder and was described in QST in 1993.

It uses a CD4047 oscillator divider to make a nice square wave and two diodes to mix the incoming signals. In my case the oscillator is at around 600Hz. When the phase is equal no tone is heard, otherwise you hear the tone in a receiver tuned to the frequency you're hunting. Here's the board:

To try it out I used a NanoVNA to generate a CW signal. Here's a demo:

It's available as a kit but they kindly make the circuit easy to find here. See https://handi-finder.com/ for full information.