Digital Modes

• There are lots of Digital Modes.• The oldest is RTTY (teletype - in this case

it is Radio Teletype). • The current modes are classified in sound

card modes and specialty modes.• Sound Card Modes

– PSK-31– Specialty CW modes (for satellite, EME, etc.)

Digital Modes cont’d

• Non-Sound card modes– Packet– Pactor I & II– Pactor III– Winlink 2K

• Non-Sound card modes usually uses a special hardware type Terminal Mode Controller (TNC).

Digital Modes cont’d

• Computers and the Internet has made several Modes etc.

• EchoLink is one of the major modes.

• Modes for linking repeaters etc.

• D-STAR - digital modes for repeaters and radios

RTTY

• This has been around for a long time.

• The modulations is FSK or AFSK - this is a two tone system - called Mark & Space

• FSK - Frequency Shift Keying– Shifting the Transmitter frequency

• AFSK - Audio Frequency Shift Keying– Shift audio tones

RTTY cont’d

• There are special RTTY converters (these were used in the old days), now most operators use sound cards and sound card TNCs.

• There are lots of freeware programs that you can use for RTTY, most of the sound card software has a RTTY mode. – Digipan– MTTY

RTTY cont’d

• Some of the newer transceiver has built-in RTTY receive converters (ICOM 746 for example).

PSK-31

• This is one of the newer Digital Modes.

• This is a two-tone systems, with a bandwidth of 31 Hz.

• This is a sound card type mode and uses a sound card TNC.

• Sound Card TNCs interfaces the transceiver with you sound card and also has a keying circuit.

Apple Program for Digital Modes

PSK31 Frequencies

Where to Listen - official PSK 31 frequencies:

1838.1503580.1507035.15 for ITU region 1 and region 3, and 7080.15 for region 2 *10142.15014070.15018100.15021080.150 (although most activity can be found 10 kHz lower)24920.15028120.150

* The USA is in region 2 but there is a lot of activity on

Packet

• Packet and similar modes uses a smart Terminal Node Controller

• These can run from $ 75 to $ 500 and more. They have a small computer with memory etc. and circuits to decode the modulation.

• Most of these modes are error-free.

TNC-X - KISS Mode TNC

KPC-3+

PK-232

WinLink 2K

• This is a special form of Packet (uses a packet TNC)

• You can send and receive e-mail over your amateur radio.

• It has two parts (VHF & Low Band) – VHF uses Packet– HF uses Pactor I, II, III

• Pactor III – is a proprietary mode (requires special TNC $$$$

This is Tom’s Station - You can connect to it

Using NK5Z-10

HF - Winlink 2K

EchoLink

• This is a VOIP (Voice over Internet)

• You use your computer to connect to a server and from the server you can connect to amateur repeaters all over the world, or just to another amateur (direct keyboard to keyboard).

• Some of the old timers don’t consider this amateur radio (you will have to decide).

I’m OnlineI‘m connected to Repeater K4OBX –R

(-R designates for a Repeater)

List of Stations Online at this time

I’m connected to EchoLink Server XXXX

Receiver Digital Buffer - This is sent from the Repeater Station

Rx & Tx Level Digital Tx Buffer

XXXX

• Some

XXXX

• Some

XXXX

• Some