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Day in Engineering History Archive - April 4

| 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.
Please submit significant historical events and dates for inclusion in these lists. I will be glad to include your name and birthday. Please do not submit your death date ;-)
A couple 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.

April 4

Orwell's 1984... Day 1 - Please click here to visit RF Cafe.

1821: Linus Yale, inventor and manufacturer of locks, including the cylinder or pin-tumbler lock known by his name, was born. 1826: Zénobe-Théophile Gramme, inventor of the Gramme dynamo, was born. 1850: The city of Los Angeles was incorporated. 1876: Alfred Nobel obtained a patent for his dynamite coupound.1883: American inventor Peter Cooper, who invented the first steam locomotive, named "Tom Thumb," died. 1919: Sir William Crookes, who showed that cathode rays were fast-moving electrons, died. 1929: German mechanical engineer Karl Benz, who designed built the world's first practical auto powered by an internal-combustion engine, died. 1930: The American Interplanetary Society was founded. 1932: After five years of research, professor C.G. King, of the University of Pittsburgh, isolated vitamin C. 1945: U.S. forces liberated the Nazi death camp Ohrdruf in Germany. 1968: Nobel laureate Martin Luther King Jr., 39, was shot to death in Memphis, TN. 1975: Microsoft Corporation was formed by Bill Gates and Paul Allen, originally to sell BASIC interpreters for the Altair 8800. 1976: Harry Nyquist, of Nyquist-Shannon sampling theorem fame, died. 1983: The space shuttle Challenger made its maiden voyage. 1984: George Orwell's novel, 1984, begins on this date. 1994: Netscape Communications (Mosaic Communications) was founded.


RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

Smith Chart™ for Excel
Smith Chart™ for Visio
RF & EE Symbols Word
RF Stencils for Visio

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