Digimodes

Digimodes (digital modes) are a great way to make contacts.

Benefits are:

Usually less power required than for voice
Good if you're newly licensed and/or are mike-shy.

Disadvantages:

Requires a computer or a phone app.
Often contacts are made with macros, leading to a rather impersonal-feeling QSO.

Commonly used digital modes are:

PKS31
RTTY

In order to work digimodes, you'll need a computer, with some software to create and decode the sounds. The software I use is Fldigi, which is available for Linux and Windows. You will also need a soundcard, and the cables to connect to your radio. It is possible to simply put the radio microphone by your computer speaker, and the computer microphone by the radio speaker, but this isn't optimal. Most transceivers have a data socket on the back. You can often buy a dedicated data cable for these radios.

• Yaesu 817/857/897: https://www.amazon.com/Valley-Enterprises%C2%AE-FT-100-FT-817-FT-857/dp/B0041LNISK

Some newer transceivers (Kenwood TS 590SG) emulate a soundcard. When you connect a USB cable from the radio to the computer, the computer sees a second soundcard.

Getting started instructions for Fldigi

Start Fldigi, and follow the wizard for setting preferences.
The two tricky bits are configuring the audio settings, and the rig control settings.

Setting up your rig

All these instructions assume you have a correctly matched antenna connected or a dummy load.

Power

Important note: Ensure that you turn the power down to 20% of your radio's max power. Digital modes are 100% duty-cycle, and can sometimes take a minute or two to transmit an over. I have gone through two sets of finals (expensive!) by transmitting digimodes at full power. Don't be an idiot like me! (You could possible go up to 30 or 35% for a very quick QSO with a rare station, but be careful. Finals are expensive.)

Set the ALC correctly

Unlike voice where you want as much power going out as possible, too much audio will distort your digital signal and make it less readable.
On your radio, switch your meter to ALC.
On the bottom right of Fldigi, there is a value "TX level attenuator (dB)", given as a negative number, with arrows either side to alter it.
Click the "tune" button on the top right, and alter the TX level attenuator until it is just below where the ALC would start. This is the ideal setting. Click tune again to stop.

Setting up the audio

• Select OpMode, BPSK31 from the menu.
• Select Configure, Soundcard, Audio, Devices, and check that the correct soundcard is selected.
• Click in the lower text box and press Ctrl T (transmit). If you hear sound from your speakers, this is good. Press Ctrl R (receive) to stop.

When Fldigi is in receive mode, there should be a waterfall at the bottom. This is what displays the received signals. If you are on a laptop, or have a microphone connected, you might see something, otherwise probably not.

• Now connect the line-in socket on your PC to the audio out of your radio, and the line-out socket of your PC to the audio-in of your radio. You should hopefully start seeing some audio on the waterfall.

Setting up the rig control

Ideally, you want your radio to transmit automatically when you use Fldigi. You don't want to have to operate the radio as well as the computer. If your radio is old and has a serial (RS232) port, you may need a serial (RS232) cable to connect from your computer's serial port to your radio. Newer radios like the FT857 have this support built in to their cable. And very new radios like the TS 590SG do it all over the USB cable. (The TS 590SG emulates a soundcard as well as a serial port).

• Quit Fldigi and turn the radio off
• Connect the cable up
• Turn the radio on
• Start Fldigi
• Choose Configure, Rig Control, Rig. Note there are several different methods of controlling your rig with Fldigi. I use Hamlib, but Rigcat is also common.

You will need trial and error to work out the settings. Your radio's manual will help. You might need to go into your radio's settings and see what baud rate (bps), stop bits, and other related settings are meant to be. I can't help here, as all radios are different. Eventually you should reach the stage that Fldigi shows your radio's frequency, and when you change it on the radio, it updates in Fldigi, and vice versa. Also, when you press Ctrl T, it should trigger the transmit on your radio.