View topic - SWR Sweeper PC Board version 1.0 I've made a layout for the SWR Sweeper PC Board 1.0. It has been sent to fab for a few prototype pc boards. This is essentially the circuit out of the ARRL book minus the voltage regulator. A few improvements: the encoder is wired up, and there are connectors provided for some potential expansion of this project. This SWR Sweeper Shield board sits on top of an Arduino UNO, and the DFRobot LCD board sits on top of it. The Sweeper Shield sticks out to the right and upward beyond the LCD board so the DDS-60, RF Connectors and Rotary Encoder will be accessible. Tesla (unit) (The 6th equivalent is in SI base units). Units used: A = ampere C = coulomb kg = kilogram m = meter Antenna Analyser Project This VSWR analyser looked interesting from K6BEZ. Certainly simple and low cost and probably just the thing to test the multiband SOTA antennas that I have been putting together lately. I happened to have one of the DDS modules spare and would change the Arduino module in the article to a Nano as they are compact and cheap (~$10). Screenshot Rather than build it on veroboard as per the article, I made a PCB using Eagle and the toner transfer process. The board is mostly SMD to keep it compact and these days SMD is easier anyway.
Teslascope A Teslascope is a radio transceiver that was alleged to have been invented by Nikola Tesla for the purpose of communicating with life on other planets. Even though Tesla talked about interplanetary communications on many occasions, it has never been confirmed that he built this particular device. It is sometimes associated with the 'paranormal' Hyperdimensional Oscillator. Claims The claim that Tesla created a device called a “Teslascope” grew out of Arthur H. Matthews' 1970 book, "The Wall of Light: Nikola Tesla and the Venusian space ship, the X-12" (OCLC 2094500). Matthews, who had apprenticed under Tesla at the turn of 20th the century and worked for him until Tesla's death in 1943, wrote that Tesla had designed it in order to communicate with extraterrestrial beings.
Sweeper: An Arduino SWR Scanner Bill of Materials Arduino UNO board and development cable, standard A to B typeMain Prototyping board, Twin Industries 4” x 5” 8000- Detector prototyping Arduino ProtoShield Keypad Shield v2.0 RF synthesizer regulator mount BNC SWR Bridge Parts D1,2 - 1N34A or similar germanium signal diode OR1N5711, schottky signal diode OR1N914 or 1N4148, silicon signal diodenote that both diodes should be the same type, see text for detailsR1,2 - 47, 49.9 or 51 ohm quarter watt non inductive resistors (both same value)R3,4 - 100 ohm quarter watt non inductive resistorsR5,6 - 10K quarter watt resistorsC1,2,3 - 10 nF 50-100V monolithic ceramic capacitorsPrototyping boardRight angle pin, single row, 8 pins long, 0.1” centers Pre Regulator Parts U1 LM7808 or LM7809 RegulatorC4 47 uF 16VDC or higherC5,6 100 nFD3 1N4002UNO 9V Coaxial Power Plug12Vin Anderson Powerpole
Tesla's oscillator Tesla's electro-mechanical oscillator is a steam-powered electric generator patented by Nikola Tesla in 1893. Later in life Tesla claimed one version of the oscillator caused an earthquake in New York City in 1898, gaining it the popular culture title "Tesla's earthquake machine". Description Tesla's oscillator is a reciprocating electricity generator.
Radio Frequency Safety Many consumer and industrial products make use of some form of electromagnetic energy. Because of its regulatory responsibilities in this area the Federal Communications Commission (FCC) often receives inquiries concerning the potential safety hazards of human exposure to radio-frequency (RF) energy. The information on this page provides answers and information to inquiries regarding RF Safety. Background FCC Policy on Human Exposure to Radio frequency Electromagnetic Fields
Tesla's Egg of Columbus World's Fair: Columbian Exposition Tesla presentation, 1893 Nikola Tesla, at the 1893 World's Columbian Exposition, demonstrated a device he constructed known as the "Egg of Columbus." It was used to demonstrate and explain the principles of the rotating magnetic field model and the induction motor. Tesla's Egg of Columbus performed the feat of Columbus with a copper egg in a rotating magnetic field. The egg spins on its major axis, standing on end due to gyroscopic action. Tesla's device used a toroidal iron core stator on which four electromagnetic coils were wound.
ALERT: AAEM Releases Recommendations EMF and RF Exposures (7/12/12) These recommendations by AAEM, just released on 7/12/12, will take the world by storm. AAEM recommends that patients with a broad range of medical conditions avoid sources of EMF and RF radiation, especially smart meters on patients’ homes and on neighbors’ homes, nearby. These AAEM recommendations may be useful for accommodation requests. Tesla electric car The Tesla electric car anecdote refers to a supposed Tesla invention described by a Peter Savo (who claimed to be a nephew of Tesla), to one Derek Ahers with the date September 16, 1967. Savo said that Tesla took him to Buffalo, New York in 1931 and showed him a modified Pierce-Arrow automobile. This story has received some debate for the fact that the car's propulsion system is said to have been invented by Tesla. No physical evidence has ever been produced confirming that the car actually existed. In light of the fact that Tesla did not have a nephew by the name of Peter Savo, the Tesla electric car story is considered to be a fabrication. A number of web pages exist that serve to perpetuate the tale.
Environmental Physicians Issue Stern Warning on Biological and Health Effects from Electromagnetic Field Exposures The American Academy of Environmental Medicine (AAEM) today issued a position paper on “Electromagnetic and Radiofrequency Fields Effect on Human Health”, including wireless technologies and smart meters. Today’s report on electromagnetic fields takes a strong stand that society must acknowledge the biological effects of electromagnetic fields, educate the population about the risks from wireless technologies, and develop safer technologies. The group, AAEM, is an international association of physicians and professionals that has been dedicated to expanding the knowledge of human health in relationship to the environment since 1965. They have been first to recognize many conditions, including Gulf War Syndrome, chemical sensitivity and the role of mold in the development of systemic illness. In its new report, “Electromagnetic and Radiofrequency Fields Effect on Human Health”, AAEM is calling for: AAEM Press Release (PDF)
Plasma globe A plasma globe with filaments extending from the inner sphere to the outer. Description The effect of a conducting object (such as a hand) in close proximity with the plasma globe glass Some globes have a control knob that varies the amount of power going to the center electrode.
ARDUINO PROJECTS This sketch will readout RF power and SWR from any SWR bridge (for example 'monimatch' type). As this 'monimatch' type of bridge is frequency dependant, the meter must be calibrated for every band. Because my primary interest was for VHF/UHF/SHF, I have foreseen positions for 6m, 4m, 2m, 70 cm, 23cm and 13cm bands - but you can use the ARDUINO readout on HF as well. If you intend to build a HF or VHF bridge yourself, there are several designs available on the web : I recommend to take a look at the information here, here , here and there ! The meter will operate in 3 modes: display instantaneous power forward in Watt en dBm, display SWR display PEP power forward (peak holding with decay) display instantaneous power forward in Watt, display SWR, and emit 'beeps' corresponding to SWR value: low tone beeps at slow rate for low SWR, high tones at fast rate for high SWR.