Contacter l'auteur / Contact the author

Recherche dans ce site / Search in this site







Ham software review

After have reviewed more than fifty HF propagation prediction programs and associated tools, and close to seventy astronomy and imaging-oriented programs, we are going to review applications dedicated to radio amateur activities. They include spectrum analyzers, satellite tracking programs, Morse code trainers, DX atlases, CAT, multi-mode decoders, and other logging programs.

All applications were tested with registered versions and in real working conditions. You will find additional reviews on

Hamscope - Easygram - Spectrum Laboratory - Spectran - SkySweeper Pro

 FFTDSP - FFT Properties - MaxMSP - AVS Audio Utilities - Audacity - Analyzer2000 - ChromaPix

Java Morse Translator - NuMorse Pro - MetaWrap - DX Atlas - DX4WIN - Echolink - HamSphere

WinOrbit - Nova for Windows - Orbitron - EME by F1EHN - TS570-RCP2

(c) 2001-2004

SkySweep, free

SkySweeper Pro

Developed by SkySweep, it is a signal analyzer and multi-mode decoder developed in Finland using an original graphic user interface, and powerful DSP functions. To not be intimidated by all its windows and functions, as soon as you launch the unregistered version, the system suggests you to run the built-in demo. Accept its proposal, because it will show you some 27 scenarii explaining each function of the program and the many decoders able to translate in clear text or image many "strange" sounds that you can hear on HF or VHF bands.

The main screen is (off-)centered around the "Configuration Editor" window, in which the user selects and set the required functions (Analysis, Generic decoders, DSP filters, signal generator, RX/TX, etc). Each function calls new windows that pop up on the screen (IQ Constellation, Signal View, Eye diagram, signal statistics, 2 bit Analyzer, 3D-FFT, Spectrogram, Chat box for mode decoding, etc). SkySweeper Pro provides a high resolution phase analyzer (HFFT) up to 262144 point FFT with a frequency resolution up to 0.04 Hz able to detect any fast periodic signal or a weak signal lost in the noise. It provides a signal power/amplitude analyzer, FIR filters and different synchronization methods to decode less common modulations like DGPS, MPT-1327 or POCSAG. 

SkySweeper Pro is able to determine automatically the signal speed, to lock automatically to the signal, to remove RFI or AC hum from a signal, and to translate most coded messages transmitted on  the air. A clock correction for SSTV is also provided in system settings. It decodes CW (speed between 10-80 WPM, tone between 300-2700 Hz), VHF packet (AX.25) or ACARS transmission, SSTV (in Scottie1, 2, DX and Martin M1, M2 modes), SYNOP, etc (this latter weather report is even translated in plain English) and many digital modes (Hellschreiber, PACTOR, SITOR-A/B, PSK31, PAM, 240 lpm HF Fax, etc) without problem. Fonts displayed in decoders are also well readable (Courier 10 or so).

About limitations, I decoded successfully a CW message up to 60 WPM, SSTV and many other modulations when the signal was loud and clear. However a CW signal slower than 10 WPM is not correctly read and a CQ 30 dB stronger than the noise but associated to "shadow pulses" as strong as 24 dB like during an Aurora or EME traffic cannot be decoded. A weak SSTV signal is not clear either. A DSP helped a little (lowpass, bandpass, modifying pitch, decreasing noise, etc) but didn't permit to get the signal out. But don't worry, many other amateurs products can't extract such noisy signals either. If you want to read audio files stored on disk, SkySweeper does only supports .WAV in mono, 8 or 16 bits/sample and a sampling rate of 11025, 22050 or 44100 samples/s. Knowing that many files are saved in 8192 samples/sec or in stereo, these limitations should be lowered.

Several modes work also in transmission connecting the PC serial port (or parallel) to the radio and using the Chat Box interface to work in CW, SSTV, RTTY, PSK31, Hell, MFSK16, PSK63, PSK125, QPSK31 or 4MFSK16. You can even receive and transmit over the Internet providing the correct IP address.

In the next release of the program, the publisher, Mikko Huttunen, will try to change the minimum CW speed to 1 WPM, support more SSTV modulation modes, and audio formats like .MP3, maybe .RA.

What is my final impression ? We cannot compare such a software with a hardware decoder like Klingenfuss' Wavecom for example that is practically able to decode anything. SkySweeper remains a software, and like all its competitors it is limited by the performance of its algorithms rather than by the hardware, in this case limited to the sound card. However, globally, with so many features gathered in an user-friendly interface it is one of my favorite programs to decode common modulations but not under too noisy conditions or too weak signals, what happens sometimes. The program provides an online manual describing each field while a tutorial is under development. 

SkySweeper runs on all Windows 32-bit platforms equipped with a sound card. A demo is available. It comes in three versions, the lastest (Professional v5.x) providing additional generic decoders and analyzers. The entry-level version 3.x Standard should already satisfy most amateurs and listeners. All versions can be upgraded.

At last, there is a SkySweeper Yahoo Group.


PADAN Group, Freeware


This is a spectrum analyzer written by Alberto, I2PHD and Vittorio, IK2CZL, members of the PAcket Digital Amateur Network group (PADAN), who created also other weak signal and QRSS programs for the amateur.

The main screen is divided in two main parts. The upper window displays the signal strength expressed in dB which gain scale (amplification) and base are adjustable. The intantaneous peak is also displayed together with the time stamp of the spectrum. The lower window displays the waterfall with in addition the magnitude of the spectrum converted in arbitrary colors. Three main palettes are available, the Horne (Blue/white) palette used by default, and two full color palettes.

Main settings are available in the "Controls" window that can be hide or remain visible on top of the screen. Depending the required sampling and resolution that goes down to 21 mHz for the slowest sampling and 23 Hz for the fastest, it provides a spectral range extending between 0-48000 Hz with a default value set on 11025 sample/sec and a resolution of 2.7 Hz. A good advice, if you need to increase the sampling over 40 kHz or the resolution, stop first the processing to avoid the program to hang, then resume. Decreasing the sampling the problem does not occur as less resources are required.

Preset mode decoders are provided for NDB, QRSS3, QRSS10, QRSS30 with a special mode dedicated to WSJT program (Meteor Scatter) from Joe Taylor, K1JT.

The water fall can be displayed in B/W or color, scrolling vertically (default) or horizontally, with time tick ranging between 1 and 60 seconds. The speed on the scrolling is adjustable, as well as the input volume and the gain. In addition several filters can be automatically set like a smoothing function (average) very useful to extract the signal from the background, a denoiser and a CW peak. At last an auto brightness control is provided if don't want to adjust the brightness and contrast manually.

Input signal can be either the microphone input on the sound card via the DAC API of Windows or a .WAV file saved on disk. A signal received online can be recorded in a .WAV file.

Spectran is now at version 2 and runs on all Windows 32-bit platforms equipped with a sound card. It comes with a very short manual in PDF format but it is not really useful as the program is intuitive.


Wolfgang Buescher, DL4YHF


Spectrum Laboratory

This is in my humble opinion one of the best audio spectrum analyzer. It was programmed by Wolfgang Buescher, DL4YHF in company with some US and English amateurs.

Like its competitors this digital signal processing (DSP) takes advantage of the computer's sound card but the author provides also an audio utility to create custom interface for any A/D converter.

This product is able to analyse weak radio signals, including QRSS, voice, and natural sounds like auroras or "pings" of meteors. The interface is intuitive and without reading the manual, in less than one hour you can master its main functionalities.

The main screen is divided in two windows. Like its competitors this program displays a spectrographic image of the sound in a spectrum ranging between 0-5512 Hz for weak signals and slow sampling, 0-22015 Hz for atmospheric noises and 0-11015 Hz for a fast sampling for a voice analysis for example with a frequency resolution for weak signals down to mHz, exceeding the stability of the sound card's clock generator. In addition, this program processes up to 200 waterfall lines per second, making it possible to decode high speed CW.

I regret only that this program is not able to display the spectrum graph at high resolution or to center automatically the graph on the strongest signal.

A decoder is provided for some time-code transmitters like MSF (60 kHz), HBG (75 kHz) or DCF77 (77.5 kHz) as well as digital amateurs modes like PSK31, BPSK, QPSK, FSK,  HELL, etc.
This program includes also signal generators with a selectable waveform, frequency, an optional modulation and noise generator.

Very complete compared to its competitors, this program uses standard hams controls and can be connected to any transceiver or receiver via the serial port. These controls include an adjustable low-pass, FIR-filters (up to 128th-order filters), variable bandwidth and cutoff, peaking, a filter with FFT convolution, but there is no automatic notch or noise canceller, excepting a humb filter to remove 50 Hz (or 60 Hz) plus harmonics.

A custom and adjustable waterfall color palette allows you to change the contrast of the waterfall display during or after have received a signal.

In the same way the frequency range is adjustable during analysis, the old part of the waterfall display being automatically redrawn without stopping the audio processing.

The audio sampling is ranging from 8000 to 44100 or even 96000 samples per second. The resolution is 16-bit ADC or about 90 dB of input range, quite impressive.

At last this program is able to process online data or to load various audio files in format such as .wav, .mp3, .au, etc and save the captured audio files in wav, and images in jpg or bmp format. The program also provides a command line interpreter to schedule various tasks.

Spectrum Laboratory is now at version 2.4 b1 and runs on all Windows 32-bit platforms. In standard mode it requires a 90 MHz CPU, 128 MB RAM and a sound card but to analyze spherics or voice at the highest sampling rate, a 1 GHz CPU is warmly recommended with at least 256 MB RAM.

A DSP tutorial is available on the author website.

OK1FIG, Freeware


Petr Maly, OK1FIG developed this very simple but performing interface (2.1 MB) around the spectrum.dll library created by R.S.Horne. This is a CW decoder displaying tunes (dit-dah) in graphical form. FFT can be set between 5512-44100 samples/sec, the power scale can be set at 30, 60 or 90 dB, the central frequency and bandwidth between 0 Hz and 20 kHz. Default values can be set using a FFT size of 512 bytes, a sampling of 5512 sample/sec, a 30 dB scale, 15 dB gain and a bandwidth of about 200 Hz or shorter. The signal moves from right to left and once it is well isolated in the middle on the screen and its power well adjusted, it becomes a very user-friendly tool to learn Morse code. I know some high speed CWers who always let this window open while working DX stations.

However this small program is unable to extract a signal lost for example 10 dB down in the noise or to help you extracting very weak or very slow signals (e.g. QRSS). If it "sees" them well, there are mixed with the noise and indecipherable. For that purpose you should select a product more complete, supporting either powerful FFT functions or QRSS mode.

Easygram is now at version 2.02 and runs on all Windows 32-bit platforms equipped with a sound card.

KD5HIO, Freeware


Glen Hansen, KD5HIO, developed this application (2.2 MB) from WinPSK written by Moe Wheatley, AE4JY. This is a multi-mode decoder for CW, RTTY, PSK31, MFSK16, FEC, and packet. It comes with a complete help and can be interfaced with MMRTTY in option. It provides interfaces for several ICOM, Ten-Tec, Kenwood, and Yaesu transceiver and also decodes .WAV files stored on disk.

The main screen is divided in three main panes, sent, receive and a scope showing either the spectrum, waterfall, input signal or data synch. You can automatically send a CQ sequence or a tune. You can manually set the decoding speed or ask the program to find it itself. You can also adjust the gain, the receive and transmit frequencies. Hamscope decodes well some QRM with the signal but globally you can work a station in CW via your keyboard without knowledge of the Morse code. It is of course better suited to digital modes that it decodes without the least error or almost.

Only drawback, Hamscope is unable to extract a weak or a very slow signal lost in the noise and the decoded text is displayed with a small font (Arial size 8 or so).

Hamscope is today at version 1.54 and is designed to run on Windows 98 and NT equipped with a sound card but it runs perfectly under Windows XP and ME as well.

(c) 1997-2002

Silicon Pixels, $120


Written by James Barber and William Montgomery, ChromaPix is an SSTV application. Taking advantage of DSP functions, it is very powerful and should satisfy the most advanced users. It comes with a superb and user-friendly GUI and an excellent manual of 41 pages to download (PDF of 3.6 MB).

The main screen is divided in 4 parts. At center is the main display where images are received and can be edited, Images controls are at left (image quality, filters, painting tools, etc), SSTV controls are displayed at right (transmit, receive, mode, tuning, etc), and Storage controls below (save, restore, print, etc).

In Auto receive mode, if the signal is strong enough, ChromaPix can detect the transmission mode or you can set it manually selecting one of the 8 modes provided, including Martin M1, Scotty S1 or Robot 72 to name a few. You can also select in this scrolling menu the sizing of your interface (from a small GUI up to full screen).

Before using ChromaPix it is warmy suggested to read the manual to understand how to configure settings and adjust images during reception thanks to SSTV controls (submenu SSTV, 1, 2, 3). This can be the case when image is tilted (slanted) due to a bad calibration of the sound card clock that creates oscillator errors. You can also rectify the image (received or to transmit) using the Dew-skew feature on the Image control.

Among additional tools name the tuning spectral display (in the SSTV controls pane) that permits to adjust the SSTV signal to the correct frequency. After reception the image can be postprocessed, its brightness, contrast, saturation, hue, sharpness and colors can be adjusted, and, to some extent, the QRM can be removed as well. Digital images to transmit can be read in various formats among them BMP, JPG, GIF, TIF, PSD, etc. and saved manually or autosaved in the same formats as well.

ChromaPix is now at version 1.6 and runs on all Windows 32-bit platforms equipped with a sound card. The Windows 95 version is sold $84. A demo is available running 30 minutes before shutting down. It also displays an "unregistered" in the upper right corner of the image in transmission.

(c) 2002-2004



Written by Thomas Braunstorfinger and Martin Hisch, Analyzer2000 is a spectrum analyzer able of fast spectral analysis, displaying FFT from the line input or a .WAV file stored on disk. An online help is provided.

FFT sizes is ranging between 256-16384 points, dynamic range up to 160 dB, base and zoom are adjustable, it supports transmission modes like PSK, CW and includes an universal FSK/F7B/FM demodulator able to decode SSTV and FAX modes.

The main screen is divided in two panels, the top one showing menus and controls, the lower pane showing several windows : FFT, a scope with envelope, a waterfall (sonagraphic analysis), a CW decoder, and an interesting FSK or PSK phase analyzer (PSK and other modes are not decoded but analyzed only). In addition several measurement tools are provided like markers, frequency rulers, level rulers, time rulers and, more intresting, methods for determination THD, SNR (SINAD) and VCO phase noise (dBc/Hz). It also includes a test generator for sinewave and/or noise stimulation (full duplex mode). Spurs as weak as 50 nV can be detected.

The CW decoder read almost error free a clear signal but has difficulties to decode it when there is noise, sferics or QRM in spite of the use of additional controls (Interference suppression, Sensitivity DX). In presence of noise the Automatic threshold must be desactived and in this case it is not easy to extract the signal and to find its correct speed, which is only labeled line/min (lmp) ranging between 14-1500. The HF Fax and SSTV decoders could be improved as they work essentially in auto mode and without fine tuning. So I only retain the product for its CW decoder. Analyzer2000 is now at version 5.04 and runs on all Windows 32-bit platforms equipped with a sound card. A demo is available running 30 minutes before shutting down.


Audacity, freeware


Developed by Dominic Mazzoni and his colleagues, Audacity is an audio editor with dedicated features that will please musicians as it includes a track editor.

This is a freeware which interface is available in 20 languages, most European, including in katakana (japanese).

Audacity is able to read and save audio files in WAV, MP3, AU, AIFF, OGG, VOX and a few other formats. 

Audacity can be quickly mastered as the interface is self-explanatory and very well designed. Most settings are set in Preferences. It samples an audio file between 8000 and 96000 Hz (default is 44100 Hz), in 16, 24 or 32-bit format, mono, stereo or up to 16 channnels. FFT size is ranging between 64 and 4096 (defaut is 256). You can also associate macros to keyboard keys or to the mouse click. At last, you can save a complete working session as it appears on screen as a "project".

When you load an audio file, its audio track (spectrum) is displayed in a time window that can be reduced or expanded using the menu option or the mouse to fit in the bakground window. Its left part includes a pop-up menu to enable/disable some features (play in mono, stereo, mute, solo, gain control) and to select the type of display : as waveform, spectrum, pitch, etc. The View menu provides a very fast FFT tool (Plot Spectrum) that also export data in TXT file. Note that Audacity can also read raw TXT file (via Project, Import Raw Data...) and inverse FFT are not hard to achieve.

Editor side, many effects are adjustable using cursors and include a "preview" mode. In all cases you have the possibility to roll back changes.

Audacity doesn't require much ressources. It works well and fast on a 500 MHz PIII CPU with 196 MB RAM. Among some drawbacks, the online help is available but not contextual, and the Index is empty at first sight; ou must click on the "Show all" button to display items. If you don't hear the files you loaded, remember that all the audio device settings are under the Menu File, Preferences. At last, whether you select Open or New file, Audacity creates each time a new session.

Audacity also imports files in MIDI format but as "project" and this is an experimental feature only. In the current version, this format is not editable and provided only for vizualisation purposes. Playing, recording and editing will be available in a next release. It includes in option several plugins like LADSPA and Nyquist programming language to write your own audio effects.

Audacity is now at version 1.2.2 and runs on Windows 98, 2000, XP, and ME, Mac OS X, Linux and many Unix platforms equipped with a sound card.

Audacity also provides a tutorial and a mailing list on its website. 

Note that its developers request your co-operation for translating the interface in other languages.

(c) 2001-2003

NCT Company Ltd, $30

AVS Audio Utilities

Audio Utilities is a very cheap but powerful audio utility that you can master in less than one hour. It is constitued of five products :

"Audio Editor" allows you to edit your audio files (WAV, MP3, AU, etc), record your own music or voice, mix with other audio or musical parts, and add effects (like Reverb, Echo, etc). It comes with various preset filters (low pass, band pass, high pass, notch, ...), several levels of amplifications (3 dB, 6 dB, 10 dB, 60%, 200%, ...) and compressions (-20 dB, -40 dB, ...), the possibility to stretch time and pitch (0-400%), copy and paste parts of the file, and more.

Windows size and color schemes can be modified as well the sampling frequency and the ouput file format. It is so simple that I use regularly to edit my radio astronomical recordings.

"Audio CD Grabber" allows grabbing audio tracks from audio CDs, downloading and uploading disc from various sources and copying them on your local hard disk. An easy way to hear your favorites CDs from your computer.

"Audio CD Writer" allows you to create audio CDs from MP3, WAV, OGG and other digital music files. As easy to use as its competitors (i.e. NERO).

"Audio Recorder" allows recording audio data from various sources (mike, audio CD, etc) and create file in format such as PCM, PM3, ADPCM, WMA, etc.

At last "Audio Converter" helps you converting one audio format in another one (MP3, WAV, OGG, ADPCM, WMA, etc).

Using a PIII 500 MHz, 256 MB RAM computer, some heavy threads like the pitch or time increasing to 400% on stereo files longer than 30 sec have temporary hanged my system. Maybe it was my mistake trying to access too quickly to another submenu. But if you need to digitally process very long files I suggest you to work with at least a 1 GHz CPU and 500 MB RAM. The program uses also quite a lot your temporary directory (some hundreds MB during any process). So if your C: drive is nearly full (w 300 MB), either remove some documents or change its location before running it.

AVS Audio Utilities is now at version 1.5 and runs only on the next 32-bit OS : Windows 98 Second Edition, Me, 2000 and XP, equipped with a sound card. A demo is available.

Minus side : AVS is an "amateur" product in that sense that if it can help you to process ordinary audio files, during transformations it adds also unwanted artifacts (like generating "false" patterns when you process a very short period of time, etc). It is also unable to detect a weak signal lost in the noise. If you need a quality and powerful DSP software to process the voice signal for example, you must invest in more expensive products like Adobe Audition (ex-Cool Edit Pro, $170), Raven or even MatLab.

A custom APT signal

A custom filter (drawing my name in the lower window)

A custom Doppler effect, page in edition mode

1990-2004, Cycling'74, $495


For short, MaxMSP is a development environment to create sound recordings based on inverse FFT.  Based on C programming language, MaxMSP provides you with a high level, graphical programming language. Programs are "written" using graphical objects rather than lines of code in text mode. This reduces the learning time, providing a clear and intuitive way to write programs simply by connecting objects to each other.

Events can be triggered at any arbitrary time in the future, interfaced to MIDI and other communication protocols, and logical operations can also be performed. Applications made with Max run in real time.

Since its creation in 1986, MaxMSP evolved much and from a graphical music programming environment it has expanded to include audio data (with the introduction of MSP) and image/matrix data (with the introduction of Jitter).

MaxMSP lets you control your equipment in any way you want. You can create applications for composing, improvising, and ordering or modifying media—anything you can imagine doing with a computer using a graphical method. All control information is converted into a simple stream of numbers. Here are three examples of files processed with MaxMSP. These are short MP3 files recorded with the microphone outside the application : a custom APT signal (upper dump screen), a custom filter (drawing my name on screen, middle dump screen) and a custom doppler effect (lower dump screen, in edition mode).

If you are a beginner in programming, there is no doubt that like all evolved programming tools, you will take a lot of time to master MaxMSP. You need to download and read all external manuals provided by the publisher (in PDF and html). As it the program does not provide any help file. All help functions are in fact accessible within the patcher, when you create or edit a file.

The best way to quickly learn how it works is to load the examples included with the package (.pat for patcher) and to edit them (View, Edit). In this editing mode you can click on all objects displayed on screen and with the right-click get the help that will explain you how work the concerned object. In some examples it will suggest you to read some additional tutorials. This help is really well designed and complete. You only need time to master the package, for example in creating first a small application then a larger and more complex one.

MaxMSP is now at version 4.5.2. and runs on all Windows 32-bit with a PIII CPU minimum, and Apple MacOS plateforms. A demo is available.

(c) 1999-2004

Janez Makovsek, $89

FFT Properties

FFT Properties is a PC-based spectrum analyzer, probably one of the less expensive and the most complete FFT tool available for the advanced amateur searching a product dedicated to DSP. FFT Properties is indeed based on the Basic Delphi Signal Processing Package, aka BDSPP.

The objective of a FFT processing is to convert a signal in the time domain in the frequency domain. A FFT provides for example a mean to calculate the frequency of a fast pulsating signal or to evaluate the response of a signal converter like a sound card. It permit to check its frequency response and non-linearities. It can help you to tune a signal generator, an instrument or even your linear amplifier.

FFT Properties provides hundreds of functions to name parametric windows, peak interpolation, online wavelets decomposition, higher order spectral analysis, cross and auto correlation, cepstral and cross spectral analysis, FIR filter designer, decimation and interpolation, without to forget peak marking features, quality charts and printing capabilities.

FFT Properties is one of the few frequency analyzers able to measure with an extremely high accurate non-parametric phase angle of non-periodic signals and linear phase peak filtering. Taking advantage of multi-windowing and resource hungrier, it requires a fast PC if you want to avoid hanging.

A version 5 is under development that will provide an ultra-fast sample rate converter with SNR of over 160 dB to allow resampling of 24-bit audio signals without loss of quality in real time among other new features.

This program is now at version 3.5 and runs on all Windows 32-bit platforms equipped with a sound card. A demo is available. Without register all features will work excepted that the sampling rate is reduced to 512 samples/sec and thus will limit your ability to analyse pulsed signals. Several manual are also provided in PDF format. 


(c) 1998

Mike Cook, AF9Y, $37


Here is the most amazing amateur software I know dedicated to signal processing. If you have basic knowledges of propagation, signal/noise ratio and its meanings, traffic types and all that stuff defining the usual work of ham radios, and even if you are like me a short waves listener, this spectrum analyser can interest you.

Peculiar it is really, reason I displayed dumps of spectrum graphs with legends for convenience as these real time displays are more than hermetics for most of us at first sight.

Mike Cook, a long-time ham radio, call AF9Y, wanted an application able to detect weak radio signals in real time and even signals well below the noise level. Such applications do not exist in the amateurs world and therefore he designed himself this program. Its key features are a real time display of a color spectrum graph with 2 Hz filtering (using a 4096 point FFT), it uses an automatic color gradient to improve the visibility of signals vs the background noise,  an integration mode to detect signal below the noise, it displays on screen Moon Az/El for moon bounce traffic as well as TOD and East/West sequences and more. FFTDSP displays also true S/N measurements and bar graph, smoothing filters (hamming, cosine, etc), has a built-in zoom in/out for narrow (1300 Hz) or wide (2500 Hz) display and it is able to track object by RA/Dec.

I/O side, FFTDSP can not only record and playback waves for post spectrum analysis (using a sound card) but it can also save and load spectrum pictures.

Of course, as we expected, last but not least FFTDSP supports SETI applications through an unattended data logging monitoring. A way to compete vs Seti@home...

FFTDSP is at version 4.2 and runs in a DOS box under any Windows 32-bit platform, and requests at least a 80486 CPU with sound card. A demo is available.

Back to Amateur radio activities

Back to Reports & Comments

Back to:


Copyright & FAQ