Themes

Slow Scan Television - SSTV Main modes of operation SSTV mode table Comparing SSTV modes More comparing SSTV Links	It's sometimes difficult to obtain technical information on the different SSTV norms, and what they mean. Here are the results from my findings. (texts in Spanish for now)
Ionospheric sounders Chirpers 'Homemade' chirp plots Official chirp plots Mini chirp beacon Pulse stretcher for GPS PPS	'Chirping' is the popular name for an old technique called ionospheric sounding. A large number of stations around the world periodically send signals upwards, and then try to catch them back, evaluating the time it takes, and other parameters, and in this way analyse the ionosphere layers in height, density and composition. With modern computers, we can spy on these signals and even be able to make some conclusions on the results. These are a few examples of chirps recorded here, and from several places around the world, with very different technologies.
Propagation	Very much linked to the previous theme, on these pages you can find professionally made ionograms, and these are meant to be a didactical tool to show how the layers vary during the day and during other external effects.
Antennas Simple helix antenna Quadrifilar helicoidal antenna	Useful indication for design and construction of special antennas.

Radio

These pages are dedicated to subjects related to radio, with some bias towards propagation, which is where I am most active at the moment.

It is mainly a compilation of much loose information, which was previously under the 'University' theme, for use in my classes, but the information seemed of sufficient general interest to publish it separately.

Not all is of my hand: Most of the ionospheric sounding info was written by Peter Martinez, G3PLX, and Murray Greenman. It is republished here with their permission. The translation to Spanish is mine. Don't blame either Peter or Murray! The databases and tables are a collaboration of many people's experiences.

Please note also that some of the pages may lack in explanations. Those may be coming, but much of the information is just there as a tool for my classes at the University. Feel free to contact me...

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