Even if RTTY is a slow operating mode, it is still very popular and has therefore been integrated into the HSmodem software.

To set RTTY operation, select the appropriate transmission speed:

and then go to the RTTY window:

The yellow RX window shows all received characters. HSmodem-RTTY is full-duplex, i.e. Reception is always active, even during transmission. So you can hear your own transmission back via QO100.

The blue TX window is used for keyboard input, it is activated as soon as you are transmitting.

activate transmission:

1. press the TX On / Off button, or
2. send a predefined line. At the beginning of each predefined transmission, the system automatically switches to TX.

RTTY works with 2 frequencies, Mark and Space. These two frequencies show two peaks in the spectrum display. Reception is possible when these peaks are on the two green lines. There are two options:

1. Automatic tuning: activate RX Auto Sync
2. Double click in the spectrum window

the automatic SYNC needs approx. 1-2s for tuning. If several RTTY stations are transmitting close together, you have to switch it off and manually select the desired signal by double-clicking.

To enter the callsign and name of the QSO partner in the corresponding input fields, click on the callsign or the name in the yellow RX window, the entry is then made automatically. Manual entry is of course also possible.

There are 14 memory buttons. 8 of them are preset with the usual texts, but can be changed.

Three functions can be selected: TX, Real and Edit.

• Edit … switches to the input mode. The text can be changed as required in the text field under the buttons. Special characters are available, see help text in the box on the screen.
• Real … display of the text as it is sent out. The special characters have been replaced with real text.
• TX … pressing a memory button sends the text memory.

to do this, press one of the small buttons next to the RX or TX window.