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Feature Transmit capability Morse Code (CW) Radioteletype (Baudot) Radioteletype (ASCII) SITOR A/B NAVTEX Weather Fax (WEFAX) Packet ACARS Slow Scan TV (SSTV) PSK31 Hellschreiber ICAO Selcal ALE Automatic Link Exchange DTMF EIA CCIR Spectrum Display (FFT) Price: |
MultiMode Lite No Yes Yes Yes Yes Yes No No No No No No No No No No Yes $39 |
MultiMode Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes $89 |
NAVTEXT is a system that transmits weather and ship navigation warnings on
518 kHz longwave.
If you'd like to see an example WEFAX image, here's a
weather satellite image
that was transmitted by the US Navy, San Francisco, on 1/1/98 at 2108z on
17151 kHz.
Be sure to visit the
Official PSK31 Homepage
for detailed information about this exciting new mode.
Each character is encoded as a 7 by 7 matrix of pixels. 150 characters are transmitted per minute.
A character takes 400 milliseconds to send. As there are 49 pixels per character, each pixel is 8.163ms long.
The effective baud rate is 122.5 baud, and 2.5 characters are sent each second, for an average speed of about 25 WPM.
ZL1BPU has an excellent site devoted to Hellschreiber.
This SSTV image was received using MultiMode, as was
this one. They were both received on January 31, 1999, on
14230 kHz, using Scottie S1 mode (the most commonly used mode in North America).
ALE (Automatic Link Exchange) is a mode used by government and military stations to establish
communications on the shortwave bands.
ICAO Selcal is the two-tone system used in civil aviation to alert pilots that a transmission is
about to occur. Each aircraft in the world has it's own tone pair.
In addition, EIA and CCIR tones, used by public safety organizations, may also be
decoded. The tones used by the High Frequency Polytone (XPH) Numbers Station may also be
decoded into digits.
CW (Morse Code)
MultiMode decodes all speeds of morse code. The speed may be manually
entered, or the auto-speed
feature will automatically analyze the morse code being received, and
determine the correct
speed settings.
RTTY (Radioteletype)
RTTY of all popular speeds may be monitored. Several different shifts may
be selected, and the
polarity (normal or inverse) of the signal may be inverted.
ASCII (Computer Radioteletype)
The features of ASCII mode are essentially identical to RTTY mode.
SITOR (Marine Radioteletype)
This mode, commonly used for marine traffic, may be easily monitored.
MultiMode automatically
syncronizes to the sending station, making decoding extremely easy.
SITOR-B / FEC / NAVTEX (Marine
Radioteletype)
This mode is also commonly used for marine traffic. It is one way, and
each character is transmitted
twice, so that a garbled character may be discarded.
FAX (Weather Fascimile)
Weather fascimile (WEFAX) stations transmit weather maps, satellite
photographs, and press
(newspaper) photographs. Unlike some programs which only display 16 shades
of grayscale,
MultiMode displays all FAX images in 256 shades.
ACARS (Aircraft Communications)
This new mode is becoming more popular all the time. Much of the routine
communications of aircraft,
which used to be handled by voice, and now automatically sent using ACARS
mode. These transmissions
take place on the standard VHF Aircraft Band (118-136 MHz), and ACARS
transmissions will eventually
start on shortwave. If you enjoy monitoring aircraft, you need to be able
to monitor this mode.
Packet Radio
MultiMode can decode and display 300 baud (HF) and 1200 baud (VHF) packet radio transmissions.
Packet support is receive only.
PSK31
PSK31 is sort of a cross between CW and RTTY. Data is transmitted at 31.25 baud (hence the name).
However, unlike RTTY, and much like CW, the length of each character varies,
from a minimum of one bit(for a space) to a maximum of ten bits (for seldom used characters).
Two zero bits are sent between characters.
Hellschreiber
Hellschreiber is a method of sending text by radio. Each character is sent as an image, pixel by pixel.
It was invented in 1929 by Dr. Rudolf Hell, of Bavaria, Germany.
SSTV (Slow Scan TV)
This mode is used by amateur radio operators to send color and B&W images.
SSTV Modes Supported
MultiMode supports the following SSTV modes. Is your favorite mode not listed? Email me with the specifications for the mode, and I'll add support for it!
Robot Modes
8 Second B&W
12 Second B&W
24 Second B&W
36 Second B&W
36 Second Color
72 Second Color
Martin Modes
Martin M1
Martin M2
Martin M3
Martin M4
Scottie Modes
Scottie S1
Scottie S2
Scottie S3
Scottie S4
Scottie DX
Various Tone Modes
Many services in the VHF/UHF bands use telephone tones to transmit
information. DTMF mode allows these tones to be decoded and displayed.
Audio Spectrum Display
This mode is used as a tuning aid. A display of the audio spectrum is
shown, to allow you to
adjust your receiver's tuning for correct reception, eliminating the
guesswork of trying to
properly tune in a station.
