Prior to the middle of the 19th century, rates were based on the number of sheets in a letter and the
distance it was traveling. In 1845, rates were based on the weight of a letter and the distance it was going.
Beginning in 1863, domestic letter rates became "uniform," that is, they were based solely on weight, regardless
of distance.
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed
formulas and reference material while performing my work as an RF system and circuit
design engineer. The World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while typing up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
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and text used on the RF Cafe website are hereby acknowledged.