Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives Magazine Sponsor RF Cafe Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Alliance Test Equipment Centric RF Empower RF ISOTEC Reactel RF Connector Technology San Francisco Circuits Anritsu Amplifier Solutions Anatech Electronics Axiom Test Equipment Conduct RF Copper Mountain Technologies Exodus Advanced Communications Innovative Power Products KR Filters LadyBug Technologies Rigol TotalTemp Technologies Werbel Microwave Windfreak Technologies Wireless Telecom Group Withwave Resources Vintage Magazines RF Cafe Software WhoIs entry for RF Cafe.com Thank you for visiting RF Cafe!
Crane Aerospace Electronics Microwave Solutions: Space Qualified Passive Products

LadyBug RF Power Sensors

Windfreak Technologies Frequency Synthesizers - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low-priced products, all of which I created.

RF Cascade Workbook for Excel

RF & Electronics Symbols for Visio

RF & Electronics Symbols for Office

RF & Electronics Stencils for Visio

RF Workbench

T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads

These Are Available for Free

Espresso Engineering Workbook™

Smith Chart™ for Excel

PCB Directory (Manufacturers)

Day in Engineering History Archive - June 30

Day in Engineering History June 30 Archive - RF CafeJune 30

Special Relativity Published - RF Cafe1879: The California Electric Light Company was organized in San Francisco, becoming the first electric company formed to produce and sell electricity 1905: Albert Einstein published his theory on special relativity, "On the Electrodynamics of Moving Bodies." 1908: An unexplained explosion in Tunguska, Siberia knocked down trees in a 40-mile radius and knocked people unconscious 40 miles away. 1930: The first round-the-world broadcast from the U.S. used a series of short-wave radio relays and took one-eighth of a second. 1946: The first atomic bomb dropped from an airplane over water occurred over the Bikini Atoll onto a target group of 73 scrapped ships. 1948: The invention of the transistor was announced by Bell Laboratory. 1948: The first telephone recording devices were authorized for public use in the U.S., and required a periodic "beep" to alert the users. 1953: The first Corvette rolled off the Chevrolet assembly line (it sold for $3,250). 1961: Dr. Lee de Forest, inventor of the Audion tube, died. 1971: Three cosmonauts aboard Soyuz 11 were found dead inside their spacecraft after it had returned to Earth. 1972: The first leap second time correction was added.

| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |

Note: These historical tidbits have been collected from various sources, mostly on the Internet. As detailed in this article, there is a lot of wrong information that is repeated hundreds of times because most websites do not validate with authoritative sources. On RF Cafe, events with hyperlinks have been verified. Many years ago, I began commemorating the birthdays of notable people and events with special RF Cafe logos. Where available, I like to use images from postage stamps from the country where the person or event occurred. Images used in the logos are often from open source websites like Wikipedia, and are specifically credited with a hyperlink back to the source where possible. Fair Use laws permit small samples of copyrighted content.

PCB Directory (Manufacturers)
ConductRF Phased Matched RF Cables - RF Cafe

Innovative Power Products Passive RF Products - RF Cafe

Exodus Advanced Communications Best in Class RF Amplifier SSPAs