Contents / Overview
Program Version: Spectrum Lab V2.7 or later
Revision Date: 2007-04-11 or later (YYYY-MM-DD)
Author: Wolfgang "Wolf" Buescher (DL4YHF)
Homepage: Moved to
http://freenet-homepage.de/dl4yhf/spectra1.html,
because of problems with the old website
www.qsl.net/dl4yhf .
Revision History ("what's new") : See
revision.txt , a part of it can be found on
the above website too.
Email: Can be found on the author's homepage ("subject to
change" !)
DL4YHF's Spectrum Laboratory (short: SpecLab) is a program to...
The main window will often look like this.. there is a control bar at the left side, a spectrum graph in the upper part, and/or a spectrogram (aka 'waterfall') in the lower part. The screenshot shows a few VLF transmitters on a spectrogram in Radio-Direction-Finder mode.
Spectrum Lab is intended mainly to be used for amateur radio experiments, but you may also try it for something completely different as long as you keep in mind that this program is still far from being "professional" software ! Because this program is freeware, the entire risk of its use is with you.
Because of a lack of time, there is no translation of this manual into German and other languages.
Aus Zeitmangel gibt's leider noch immer keine deutsche Übersetzung dieses Handbuchs (die würde dem englischen "Original" eh ständig nachhinken), nur eine Kurzanleitung in deutscher Sprache.
Just an overview and a lot of links to places in the manual. Maybe you'll find here what you are looking for... if not, use the "backward"-button of your browser.
Very Low Frequency Receiver (local link)
Started as an experiment to receive historic transmissions from Grimeton
radio (SAQ) in the longwave spectrum. The program runs as a software receiver.
Almost no external hardware required. An antenna is connected directly to
the soundcard's input. The input from the soundcard is converted into the
audible spectrum (about 650 Hz), passed through a narrow-band audio filter
and fed to the soundcard's output.
Natural Radio Receiver (local link)
Describes how to use Spectrum Lab to improve the quality of your natural
radio reception *by software*. Uses Paul Nicholson's multi-stage comb filter
to remove AC hum and harmonics in the audio spectrum. You can add up to 32
other independent notches to remove other unwanted signals, like 70 Hz from
PC monitors, or add lowpass / highpass filtering if needed.
I/Q Processing (local link)
I/Q processing is one of the keys to software-defined radio (SDR). Though SL wasn't designed as easy-to-use interface for an SDR, it can be used as such: Not only as a broadband waterfall display (with quadrature inputs), but also as modulator + demodulator + test signal generator with I/Q in- and/or outputs.
A LowFER Receiver Using a "Software" IF (web link, added here 2006-04)
This article by Lyle Koehler, KØLR, describes a "software defined" receiver, and some other (easier-to-use) alternatives to SpecLab too. Don't miss Lyle's simple downconversion circuits which he sucessfully uses to the receive US-American LowFER beacons. The last part describes how to log fieldstrengths of LowFER beacons with Spectrum Lab's plot window.
Automated LF monitoring facitily (web link; address updated 2003-03)
Created and operated by Brian, CT1DRP (a radio amateur from Portugal operating on longwave). This systems continously records signals on the 136kHz band, analyzes and logs some parameters using the file export function. The resulting graphs are frequently updated.
Measuring the signal strength of low-duty-cycle beacons (local link)
Used for propagation studies on shortwave. Radio amateurs all over the world operate becons on certain frequencies (like 14.1 MHz). These beacons periodically transmit a carrier and their identifier in Morse code. Some of these beacons have a very low duty cycle but a precise interval, for example 1 second carrier and 3 minute interval. This application takes precise readings of the signal strength, and writes the result into a text file which can be post-processed with a spreadsheet program etc.
The Eart-Venus-Earth experiment was a successfull attempt by Amsat-DL to receive own 2.4 GHz echos from Venus. This required incoherent averaging (because of the spectral broadening of the microwave signal). Details can be found on the AMSAT-DL website, and in the AMSAT-DL Journal #2 / June 2009 .
The complete help system was originally written in HTML. Spectrum Lab tries to open the pages and jump to a named location (called an "anchor" in html) when a help button is clicked. This used to work perfectly well until the advent of internet explorer 7 !
In IE6, it was possible to open an html document, with the anchor appended after the '#'-character. For example:
iexplore c:\cbproj\speclab\html\index.htm#about_help
opened this document in the internet explorer, and jumped directly to the anchor "about_help". No idea why this doesn't work with IE7 - it simply ignores the "anchor name" passed in the command line.
So, after "upgrading" (?) from IE6 to IE7 you will have to find the chapter with the info you're looking for yourself.
If anyone knows how to tell IE7 to load a certain document and to jump to a certain anchor through the command line, please let me know.
To circumvent this problem, Spectrum Lab now looks for a OPERA first, and for FIREFOX. If any of these internet browsers is installed, it will be launched to show the requested help page (and jump to the named anchor in the URI, which worked perfectly with these browsers when tested with the up-to-date versions of OPERA and FIREFOX in April 2007).
Only if neither OPERA nor FIREFOX can be found, the help system will use the default browser (which, under windows, will usually be IE, which caused the problems mentioned above).
This software is provided 'AS IS' and any express or implied warranties, including, but not limited to, the implied warranties of merchantability(*), fitness for a particular purpose, or non-infringement, are disclaimed. In no event shall the author or contributors be liable for any direct, indirect, incidental, special, exemplary, or consequential damages (including, but not limited to, procurement for the substitute of good or services, loss of use, data, or profits; or business interruption) however caused and on any theory of liability, whether in contract, strict liability, or tort (including negligence or otherwise) arising in any way out of the use of this software, even if advised of the possibility of such damage.
In other words, the entire risk is with you ! (what else would you expect from a freeware..)
Namings for products, that are registered trademarks, are not separately marked in these documents. The same applies to copyrighted material. Therefore the missing (tm), ®(r), or ©(c) does not implicate, that the naming is a free trade name. Furthermore the used names do not indicate patent rights or anything similar.
Early soundcard routines were inspired by the WinPSK31 sources by Moe Wheatley
and Dave Knight .
ASIO support was added using the ASIO SDK by Steinberg .
JPEG support was added using the JPEG library (c) 1994-1997, Thomas G. Lane
.
The Multi Stage Hum Filter is based on sources by Paul Nicholson .
The Colour Direction Finder is based on a work by Markus Vester .
Other contributions were made by members of the RSGB LF Group .
Support for PERSEUS was added using a Software Development Kit (SDR-DK)
"Copyright Microtelecom s.r.l. – Pavia di Udine, Italy".
Support for SDR-IQ / SDR-14 is based on sample code provided by RFSpace and
MoeTronix .
last modified (YYYY-MM-DD): 2007-04-11