SAQrx VLF Receiver

SAQrx is a soundcard based USB (Upper SideBand) receiver covering 0-22 kHz. The filter bandwidth is selectable in three steps, 300, 1000 and 2400 Hz.

SAQrx was written primarily for reception of the 2006 Christmas transmission from SAQ but it was made tunable so it can be used for other purposes while waiting for the next SAQ transmission :-)

SAQrx requires a soundcard capable of full duplex at 44100Hz sampling frequency. Most soundcards can do this.

SAQrx Screenshot

More information about the old longwave transmitting station SAQ, which was declared as a world cultural heritage by UNESCO in 2004, can be found at and at Wikipedia.

Installation is simple: Download (below) and unzip the file in a folder of your choice. There is only one file, SAQRX.EXE, just double click it to start the program. SAQrx has only been tested on Windows XP but may run well on some other Windows versions too.

Removal is even simpler: Just delete the file SAQRX.EXE.
(Unlike many other Windows applications, SAQrx will not create a lot of strange files all over your hard disk, it doesn't write any file at all, neither does it write anything to the system registry.

The SAQrx program is believed to be totally harmless, I have never heard of any problem, but YOU ARE USING IT AT YOUR OWN RISK!

Available files (download from "Attachments" section below):

  • - The executable SAQrx program (zipped).

  • saqrx.pdf - Describes how SAQrx works (this file is also included in the full source code package (below).

  • - Full source code, All files needed to compile with Dev-C++ (free) are included.
73 de Johan SM6LKM
Johan Bodin,
12 Jul 2010 02:59
Johan Bodin,
12 Jul 2010 02:51
Johan Bodin,
12 Jul 2010 03:00