HF Digital Amateur Radio

From The RadioReference Wiki

Amateur Radio Digital Operations

Ham radio on HF is not only about voice and CW (Morse Code) - there's a considerable amount of digital transmissions too. There are even digital mailboxes as well as experiments using Digital Radio Mondiale (DRM)

This page is an introduction to this topic - please feel free to add or correct anything found here. It's not intended to be comprehensive, but does touch on all the topics you will need to consider before getting involved in this side of the hobby.

This topic is discussed in the Amateur Radio Data Transmissions forum.

General Information

  • Digital amateur signals are restricted to certain portions of the bands. Here is a general list of bands which shows the sections restricted to CW (Morse Code) and digital

Where Can I Find Information on the Various Modes?

This listing is not complete, but it gives a good representation of the various modes you will find on the HF Amateur bands. Please feel free to substitute links, and add modes that are not listed here. Many of these links are courtesy of the Signal Identification Guide wiki

  • VARA (via the SigID wiki}

Digital Services (email, etc.)

Digital Voice
  • EasyDRF
    • Newer and Improved version of WinDRM

Waterfall Samples
VARA Waterfall

How Do I Connect My Transceiver and PC?

There are still some folks that connect their transceivers to a Terminal Node Controller or TNC (such as the Kantronics KAM-XL). There are several advantages - transmit keying, isolation and audio are all handled in a single box. Unfortunately sometimes these TNCs are a bit limited in the modes they cover. Without firmware updates, you are limited to the modes the TNC covers.

Far and away the more popular way to go is via the soundcard. There are several models such as the Tigertronics SignaLink. These devices remove the restriction of only working on some modes - there's usually a wide variety of software vailable, and in this case, all the transmit keying and audio is also in a single box.

There are other soundcard devices that simply feed audio back and forth from the transceiver, but you would need to build your own keying circuit for your transceiver. Fortunately there are many such schematics on the web.

See the HF Hardware Decoders page for examples of each. WM2U's Soundcard Interfacing might be a source of information for interfacing with older transceivers.

The next challenge is to determine how to wire the microphone or other jack from your transceiver to the PC or TNC. This varies from model to model, and can be difficult to determine without a manual. There are numerous mailing lists devoted to particular model(s) of transceivers (and various applications). These are likely sources of information.

What Software Can I Use?

This list is just a sample of some of the more popular (and some lesser-known) packages that can copy some or all of these modes. Additions are solicited. There are also several websites with audio (and sonogram) samples of many digital modes to aid in learning what a particular mode sounds and looks like.

Audio Samples

Listings for Tigertronics Modems

Slow Scan TV (SSTV) Applications

Testing Receiving Data on Your New Setup

The single best way to test receiving data would be to have a station with a known schedule. W1AW has such a schedule - the website for the schedule is here

Where Can I Find Additional Resources?


Mailing Lists and Forums