The RL Drake Company of Ohio history written by Bill Frost (WD8DFP) Service Department Manage, R.L. Drake Co. Click Here On his site you can find everything Drake right down to the service manuals….
Tag: the rest of the story
21 April 19
Learn Code, practice code, even earn a certificate…. The ARRL sends code daily at different speeds for those wishing to earn a Code Proficiency Certificate For the ARRL schedule Click Here
19 April 19
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After Hertz received his professorship at Karlsruhe he was experimenting with a pair of Riess spirals in the autumn of 1886 when he noticed that discharging a Leyden jar into one of these coils would produce a spark in the other coil. With an idea on how to build an apparatus, Hertz now had a way to proceed with the “Berlin Prize” problem of 1879 on proving Maxwell’s theory (although the actual prize had expired uncollected in 1882). He used a Ruhmkorff coil-driven spark gap and one-meter wire pair as a radiator. Capacity spheres were present at the ends for circuit resonance adjustments. His receiver was a simple half-wave dipole antenna with a micrometer spark gap between the elements. This experiment produced and received what are now called radio waves in the very high frequency range.
Click Here for more from Wikipedia ….. Also … American Association for the Advancement of Science
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In every amplifier circuit, the input resistor is critical. Any noise at the input signal will be amplified to the full gain. It is therefore of high importance to choose a low-noise resistor at the first stage, as well as a low resistance value. This is however not valid for a load resistor, since the gain that is obtained from a high resistance value outweighs the higher noise level. Because thermal noise is temperature dependent, it is very effective to cool the input stages to reach a low-noise performance.
Noise is an unwanted phenomenon for resistors. For some applications the noise properties are important. Examples are high gain amplifiers, charge amplifiers and low-level signals. Resistor noise is often specified as micro-volt, noise per volt of applied voltage, for a 1 MHz bandwidth. Thermal noise is the predominant source of noise for resistors. It is dependent on three variables: resistance, temperature and bandwidth.
Read more http://www.resistorguide.com/resistor-noise/
Johnson_noise_intro8 April 19
A Couple of links on Barbara Dunn…. Glow Plugs site, article and pictures of her set up… The Ham Gallery , a Tribute page and article with pictures and her license
7 April 19
Wouff Hong is just one of many folk lore… More about this click the links below…
Everything2’s article … Quirky Ham Radio Gadgets from Yesteryear (with Pictures) … A good article by KG2IC ….