RTTY
RTTY, or radioteletype, is the oldest, besides CW, digital mode there is. Yet today there is still use for this old mode. Though amateurs have largely forgone RTTY in favor of other digital modes like PSK, there is still some RTTY activity on the air, and when there's a RTTY contest you will find the bands full of RTTY signals.
RTTY is an FSK (Frequency Shift Keyed) mode that uses a signal which switches between two different frequencies. One frequency is the mark and the other is the space frequency. RTTY uses a 5-bit code, which means that only upper-case letters, numbers, and limited punctuation can be sent. Other modes such as ASCII or PSK use a 7-bit code which means that all standard ASCII characters can be transmitted. But RTTY is still a fun mode to operate and still used in the non-amateur utility HF bands.
I first began operating RTTY back in 1994 when I bought a Kantronics KAM all-mode TNC for packet & other digital modes. Today I use a PSK31 program called Winwarbler which also includes the ability to operate in PSK63 and RTTY modes. Since I already have the interface I built for PSK, it works equally well when operating RTTY. There are many different RTTY programs available on the internet, both for just listening and also for transmitting.
Operating RTTY is very simple. The format is similar to CW in that you will send CQ DE and your callsign in order to try to make a contact. However, a tuning signal known as RY's are often sent. A typical CQ call may look like this:
RYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRY
CQ CQ CQ DE N2UHC N2UHC N2UHC K
CQ CQ CQ DE N2UHC N2UHC N2UHC K
CQ CQ CQ DE N2UHC N2UHC N2UHC K
PSE KKKKK
All standard Q-codes apply in RTTY just as they do in CW. One difference is that when a typing error is made, it is standard practice to send XXXXX instead of EEEEE as in CW.
You don't have to be a good typist to be a RTTY operator, but it does help! Amateur RTTY is typically sent at 45 baud, which works out to about 60 WPM. I will generally "type ahead" before sending, which means entering text into a buffer before transmitting. The Winwarbler program allows you to do this easily buy simply typing into the transmit text box before pressing the F2 transmit button. However, even if you're a slow typist it won't matter much, since most RTTY signals will simply "diddle" between keystrokes, which means an idle RTTY signal will be sent.
Amateur RTTY is usually sent with a 170 Hz shift, which means there is 170 Hz between the mark & space frequencies. In the utility HF bands various speeds & shifts are used, however on the amateur bands it is usual practice to send 45/170.
The frequencies used for amateur RTTY are normally about 80-100 kHz above the bottom of the band. For example, on 20 meters, you want to start looking around 14080 and upwards for RTTY. On 30 meters, though, the upper part of the band around 10.140 and up will be where you will want to operate. There are also a lot of other digital modes in the upper part of 30 meters.
RTTY may be an old mode, but it still can be fun for anyone interested in getting into digital modes.