Digital Modes
Not all modes are appropriate for every type of communication. Let’s look at “quick hits” versus detailed communications. Then there are the beacon types. While this is a summary, you can use these links to get more information: FT8, JS8, Winlink, APRS, WSPR, FLDigi, and VaraC.
“Quick Hits”
In this category are things like radiograms and short messages, like a weather report. While most digital modes can handle this, some are better suited for this.
JS8, FT8, APRS, FLDigi, and DMR are suitable for this. JS8, like FLDigi, is more chat-based (though FLDigi has form capabilities), so it’s suitable for a quick message.
FT8 includes a set of generated messages, but you can replace them with anything you want.
APRS is usually thought of as a position beacon, but it also handles messages. Check out the weather stations reporting on https://aprs.fi.
DMR can be used for long conversations, but remember that we are tying up the channel. Here, it isn’t about the medium but the amount of time we are taking up. As with JS8 and FLDigi, we are not limited by the mode but by the fact that we share the frequency. Imagine reading a list of equipment needed over DMR or trying to do multiple sends on JS8.
Detailed Information
This is the long list of supplies, conditions, shelters, or other critical information. In perfect conditions, these would be via fax or email.
Modes that can send files or forms are best here. These include D-Star, Winlink, FLDigi, and VaraC. From what I have worked with so far, Winlink forms seem superior. Someone with the same form will see it in that form, the data is passed as an attachment as well as in the body, and a PDF can be sent to internet addresses. Adding the ability to handle point-to-point communications and monitor that the channel is clear before you hit transmit makes this a valuable tool. The VARA connection mode is a high-speed HF transmission mode.
A note about VARAC, I have recently discovered this when I was looking for the VARA modem for HF, and have not had the time to try it out. Like FLDigi, you can send images and files, and it has an EmComm component, so look for updates to this as we go.
Beacons
The last group is beacons. They have immense value because they can be used to measure conditions, such as propagation, and to announce locations. Let’s say someone is reporting conditions. With their radio reporting locations, you will know where they are when they send their report (essential to keep them safe and to report locations that are not reliant on road signs or other markers that could have been destroyed).
As you saw with the APRS ones, they can also send more information than just locations.
I will also add JS8 and WSPR here as tools to obtain propagation information. Having something like that running, reporting SNR, can give you a live report of changing propagation conditions.
