I have been aware of FreeDV for many years. It is a digital voice mode for HF radio. The bandwidth is approx. 1.5kHz and will likely be lowered as it continues to develop.
I decided to finally give it a look a couple of weeks ago. I watched a couple of YouTube videos to get a flavor of it, and went to the website to download the software (https://freedv.org/).
A standard SSB transceiver should work, but you will need a similar FT8/FT4/PSK31 etc setup for FreeDV. You need a signal from your radio going to a computer, and you will need audio from your computer to go back to the radio. You won’t use your radio microphone, but some type of mic connected to the PC. This is common on most modern radios (last 10 years) and some even older. It can be done on older radios with more effort. I won’t go into details, I’m sure there are many resources online to help with this.
It wasn’t too hard to install and setup. I run it on Windows 11. There is an easy setup wizard. You’ll need to select the correct audio devices. Again, this is not meant to be a tutorial, but my experiences using it briefly.
There is a feature with FreeDV called FreeDV Reporter. It can be selected from the FreeDV window menu. This will show all stations using FreeDV (if they enabled FreeDV reporting), including their frequency, version, mode, status, etc. Stations transmitting are in red, stations receiving the TX station will be in Blue. There are many ways to sort and filter the info. But to see who is online and listening or transmitting is handy.
I listened a few times the first few weeks. At first on 20 meters. I would see stations transmitting, but I was not hearing them. But every once-and-a-while I would suddenly hear some audio. Sometimes very clear, other times garbled. There is a SNR indicator in the software, and I just was not getting strong enough signals.
It seemed that there were not enough people on and transmitting and nobody was strong.
I found out there was a net on Tuesday nights at 9PM. So last week I tuned in and was pleasantly surprised to copy most of the stations. I was going to check-in when suddenly we lost all power (5th time in 2.5 weeks and second day in a row).
So I tried again tonight, and again I was copying most stations. When they came around to me I checked-in and they gave me good audio reports. There is a tool in the software to check your audio levels, and I made sure mine was about where it should be.
I have not done any comparisons with SSB. Others have, and posted online. Supposedly FreeDV is superior to copying a weak station on SSB. No way for me to say without doing more testing.
When signals are strong enough, the audio is good. If not, there will be droputs and digital artifacts on the audio. This could be annoying with QRM and QSB, but whether SSB would be copyable is the question.
Not sure where this will go. It doubt it would replace SSB. Contesting would not likely work well. Fine for ragchewing and to experiment with. Flex now is supporting FreeDV on some models, and I would expect more will in the future.
I look at it as just another mode and something interesting to play with.
