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About RF Cafe
1996 - 2022
BSEE - KB3UON
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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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February 1970 Popular ElectronicsTable of Contents
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April 1985. All copyrights are hereby acknowledged. See all articles from Popular Electronics.
LSI Gives Semiconductors a "Trip"By Vic Bell
|1.||LSI is being used to "dope" many new types of semiconductor materials.||TRUE____ FALSE ____|
|2.||If the third color band on a resistor is silver or gold,
the resistor is either a 10% or a 5% unit and is less than
||TRUE____ FALSE ____|
|3.||Spreading the outside plates on a variable air capacitor decreases its maximum capacitance.||TRUE____ FALSE ____|
|4.||When two dissimilar metals are joined and heated, a voltage is developed across their junction. This is known as the Seebeck effect.||TRUE____ FALSE ____|
|5.||"Skating force" is the side pressure exerted on a phonograph tone arm by the record groove spiral. It can be eliminated by using a dynamically balanced tone arm.||TRUE____ FALSE ____|
|6.||A magnetostrictive material is one that changes its physical dimensions when magnetized.||TRUE____ FALSE ____|
|7.||When a coil is wound around a magnetostrictive material core, a voltage is developed across the coil if a pressure is applied to the core.||TRUE____ FALSE ____|
|8.||The Curie Point of a material is the temperature where it becomes radioactive.||TRUE____ FALSE ____|
|9.||The resistances of both tungsten and carbon are inversely proportional to temperature.||TRUE____ FALSE ____|
|10.||The combination of two 10·ohm, 1/2-watt resistors in series will have the same power rating as the combination of two 40-ohm, 1/2-watt resistors in parallel.||TRUE____ FALSE ____|
|11.||Infrared detection systems are of little use in desert areas because of the high sand temperature.||TRUE____ FALSE ____|
|12.||The SCR is the solid-state equivalent of the d.c. latching relay.||TRUE____ FALSE ____|
|13.||Submarines are capable of radio communications while submerged by using the SHF band.||TRUE____ FALSE ____|
|14.||Rare earths now being used in color picture tubes are not really rare compared to many other elements.||TRUE____ FALSE ____|
|15.||Coaxial cable cannot be made substantially smaller because frequency response dictates its size.||TRUE____ FALSE ____|
|16.||An anisotropic magnet is one which has the same magnetic characteristics along any axis or direction.||TRUE____ FALSE ____|
|17.||The first half of the horizontal sweep in a normal TV receiver (left side of the screen) is formed by the damper circuit.||TRUE____ FALSE ____|