472kHz.org

Weak signal modes

Software

The download links refer to a direct download of the recent version of the software per 22/08/2017 (this may be updated from time to time). But keep in mind that some software packages are still in constant evolution and more recent versions might be available. Check the websites if you want to ensure to download the most recent version.

Argo

Function: DSP receiving software
Operating system: Windows 95 and up
Author(s): Alberto di Bene, I2PHD & Vittorio De Tomasi, IK2CZL
Description: Argo is a program to visually show QRSS, DFCW and other slow digital signals, into an easily configurable waterfall, taking its input from the PC sound card.
Status: Freeware
Website: here
Download: v1 build 145

Crunch

Function: DSP receiving software
Operating system: DOS
Author(s): Bill de Carle, VE2IQ
Description: A completely different approach to 'decode' QRSS transmissions is made by VE2IQ. With crunch the incoming audio signal is recorded as a WAV-file, either using the sound card or VE2IQ's Sigma-Delta DSP board. Afterward the file is filtered and 'speeded up' to bring the QRSS signal to normal speed CW, audible via the sound card.
Status: Freeware
Website:  
Download: v2.8

Jason

Function: Jason transmitting and receiving software
Operating system: Windows 98 and up
Author(s): Alberto di Bene, I2PHD
Description: A keyboard-to-keyboard communication program, tailored for very low S/N ratios, based on the IFK technique, using only 4 Hz bandwidth.
Status: Freeware
Website: here
Download: v2.8

Opera

Function: Opera transmitting and receiving software
Operating system: Windows 3.11 and up
Author(s): Jose Alberto Nieto Ros, EA5HVK
Description: A weak signal mode basically meant for propagation study.
Status: Freeware
Website: here
Download: v1.6.4

QRS

Function: QRSS & DFCW transmitting software
Operating system: Windows 3.11 and up
Author(s): Rik Strobbe, ON7YD - OR7T
Description: This program is primarily intended to be used for QRSS and DFCW but has also some normal CW facilities. Keying of the transmitter and frequency shifting (for DFCW) is done via the serial or parallel port, using a very simple interface. Various options are available, including QSK and fast CW identification in QRSS and DFCW modes. In 'QSO mode' the program is optimized to share the screen with receiving software.
Version 3.17 is Win3 compatible but will not support the parallel port under WinNT and up. Version 4.14 has full support of the parallel port but requires at least Win98.
Status: Freeware
Website: here
Download: v3.17 or v4.14

Spectrum Lab

Function: DSP receiving & transmitting software
Operating system: Windows 98 and up
Author(s): Wolf Büscher, DL4YHF
Description: Spectrum Lab incorporates a amazing number of features in a single program. Besides the 'standard' DSP receiving window you can use it as a terminal for PSK, RTYY and so on. It can also be used as a real time audio filter or to send and receive audio streams, possibly with timestamps from a GPS receiver, over the internet.
Status: Freeware
Website: here
Download: v2.92 b01

WOLF

Function: WOLF transmitting and receiving software
Operating system: Windows 3 and up (command prompt)
Author(s): Stewart Nelson, KK7KA & Wolf Büscher, DL4YHF (Graphic User Interface)
Description: WOLF is a proposed new signal format and protocol designed specifically for the LF bands. It can be used for beacons and for two way communication. Unlike existing formats, which are optimized for a particular S/N (and corresponding speed), WOLF can operate over a wide range of signal levels. For example, a WOLF beacon transmits a 15-character message repeatedly. If the received signal would be adequate for conventional CW, copy will be displayed in 24 seconds. At a level barely enough for 0.4 WPM QRSS, copy will appear within two minutes. Even if the signal is another 10 dB weaker, the message can still be received. It will take from 20 minutes to several hours, depending on the stability of the TX and RX.
Status: Freeware
Website: here
Download: Graphic User Interface

WSJT-X

Function: JT9 & FT8 transmitting and receiving software
Operating system: Windows (XP and up), Linux, OS X (10.7 and up)
Author(s): Joe Taylor, K1JT (now open source and developed by a team)
Description: WSJT-X is a computer program designed to facilitate basic amateur radio communication using very weak signals. The first four letters in the program name stand for “Weak Signal communication by K1JT,” while the suffix “-X” indicates that WSJT-X started as an extended and experimental branch of the program WSJT.
This package includes also other modes such as JT4, JT65, QRA64, ISCAT, MSK144 and WSPR.
Status: Freeware
Website: here
Download: here

SlowJT9

Function: JT9-1, JT9-2, JT9-5 and JT9-10 transmitting and receiving software
Operating system: Windows (XP and up)
Author(s): Rik Strobbe, ON7YD - OR7T
Description: SlowJT9 was born out of the idea to to revive the slower JT9 submodes that initially were supported by WSJT-X, but abandoned at an early stage. On the 2200 m and 630 m bands these submodes can be useful for weak signal (DX) communication.
Rather than developing a new decoder, the existing JT9 decoder of the WSJT-X suite (JT9.exe) was used. As this decoder will only decode JT9-1 (1 minute cycle JT9), the slower submodes are resampled to JT9-1 and then decoded. SlowJT9 takes care of this resampling and provides a WSJT-X like user interface.
Status: Freeware
Website: here
Download: here

WSPR

Function: WSPR transmitting and receiving software
Operating system: Windows (XP and up), Linux
Author(s): Joe Taylor, K1JT (now open source and developed by a team)
Description: WSPR implements a protocol designed for probing potential propagation paths with low-power transmissions. Normal transmissions carry a station's callsign, Maidenhead grid locator, and transmitter power in dBm. The program can decode signals with S/N as low as -28 dB in a 2500 Hz bandwidth. Stations with internet access can automatically upload their reception reports to a central database called WSPRnet, which includes a mapping facility.
Status: Freeware
Website: here
Download: Windows v2.12Linux v2.11

WSQCall

Function: WSQ transmitting and receiving software
Operating system: Windows 2000 and up (Vista can cause problems)
Author(s): Con Wassilieff, ZL2AFP & Murray Greenman, ZL1BPU
Description: WSQCall is a Weak Signal QSO mode for LF/MF. It uses Incremental Frequency Keying (IFK), making it moderately drift-proof and easy to tune. The symbol rate is very slow (about two seconds per tone), but each individual tone transmitted carries a surprising amount of information, resulting in a typing speed of better than 5 WPM.
Status: Freeware
Website: here
Download: v1.0 or DL4YHF's extended variant of WSQCall

  

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