Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.

Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.

I make no claims for technical accuracy, good design, or necessarily even originality for the contents of these pages. Rather, I am a simple enthusiast attempting to convey my love and enjoyment of radio, electronics, and computing and perhaps to inspire YOU to build something too. The following pages document projects that I have built over a period of 30 years. Wherever applicable I have named sources and references.

Radio Hobbyist’s Designbook or RHdb (for short) was designed to guide you into design of
electronics apparatus that relates to radio. It assumes you know something about electronics
but you can skip Chapters which cover familiar subjects. Mathematics needed in design is down
to simple algebra and trigonometry. Topics cover the frequency spectrum of DC through VHF.

You must supply the brainpower. But RHdb can be your main reference, a guidance toreaching
your personal hobby goal. RHdb is written in a sort of Reader’s Digest format: Short and
to-the-point, covering things simply with a minimum of words. Grouping is in 5 sections as
givenbelow with a synopsis of Chapters

The original AirBoss was made by my Grandfather (KR4LO) in order to help ham radio operators deploy their antennas over tall trees. I, the Grandson, have taken over the production of the AirBoss. Olah Technologies LLC will continue to bring you the AirBoss and other innovations.

WORLDWIDE DX CLUB "Top News", compiled by Wolfgang Bueschel

You have probably heard people talk about ionosphere virtual height. What is it and why is it important for HF propagation?

Slow Scan Television (SSTV) images transmitted from the International Space Station and other ARISS supported satellites

This site will be the focal point for some of the best SSTV images received during Oct 2008 and beyond. Images will be downlinked by ISS on 145.800 MHz. To view some of the received images transmitted from the ISS

The General Radio Experimenter was a revolutionary magazine, that offered students, engineers and hobbyists invaluable content and applications for electronics.

Organized by year for easier browsing, following are links to every General Radio Experimenter, over 500 issues, that span the 1920's through the 1970's for viewing and download.

Radio-Electronics was an American electronics magazine that was published under various titles from 1929 to 2003. Hugo Gernsback, sometimes called The Father of Science Fiction, started it as Radio-Craft in July 1929. The title was changed to Radio-Electronics in October 1948 and again to Electronics Now in July 1992. In January 2000 it was merged with Gernsback's Popular Electronics to become Poptronics. Gernsback Publications ceased operations in December 2002

The Universal Radio Hacker (URH) is a complete suite for wireless protocol investigation with native support for many common Software Defined Radios.

Motorized 10-80 Meter Adjustable Dipole