A motley collection of ideas
Hunting meteorological radiosondes is one of the exciting pastimes of amateur radio enthusiasts.These small instruments—launched into the stratosphere by meteorologists using hydrogen balloons—must be tracked by receiving their signals and following their trajectory based on their GPS data until they land somewhere. And those who are skillful may even take the “prey” home and give … Read more
In Hungary, the use of radio frequencies is regulated by the National Media and Infocommunications Authority (NMHH). The NMHH has published the National Frequency Allocation Table and Frequency Use Regulations. Radio Frequency Bands Abbreviation Frequency Range Wavelength ELF 3 Hz – 30 Hz 100,000 km – 10,000 km SLF 30 Hz – 300 Hz 10,000 … Read more
Spotters, SWL (shortwave listening) enthusiasts, and amateur radio operators all enjoy listening to aircraft communications — and nowadays, even drone pilots find it useful to monitor air traffic. A good handheld airband transceiver easily costs well over a hundred thousand forints, whereas the device described here is dirt cheap by comparison. Of course, it’s not … Read more
The Grid Dip Oscillator (GDO) is one of the most important instruments for amateur radio constructors. It was primarily used for tuning resonant circuits, but with a bit of ingenuity, it has a wide range of applications. The following text introduces this instrument and some of its potential uses, without aiming to be exhaustive. I … Read more