Short wave radio

If a short-wave radio station broadcasts on a frequency of 9.065 megahertz (MHz), what is the wavelength of the radio waves ... 

This frequency is in the short-wave radio region. Many simpler spectrometers operate at this frequency. 

Because electrical lines may be knocked out by emergency events, it is recommended that one or more cellular telephones be maintained in each of the facilities identified in Table 6.1 to be able to call for help and communicate with family members. Communicating with rescue workers and family during an emergency event will help minimize some of the psychological effects that may be experienced. Each building should also maintain one or more battery-powered AM/FM or short-wave radios and several sets of replacement batteries. The radios can be used to obtain updated reports on emergency response efforts and other useful information. 

TV transmissions Short-wave radio transmissions Satellite transmissions Electrical blankets Appliances Light bulbs... 

Stationery Communication devices Permanent ink markers, biro, pencils, elastic bands, etc. Mobile phones or short-wave radio if no mobile phone coverage... 

April 17, 1944. It was really a thrill to hear your voices via short wave radio the other night. .. Saturday morning I was in Panama City after spending my first night at the Tivoli Hotel, which is quite picturesque. At 11 AM I went to the Radio Company and made my reservation for 8 PM from Cristobol. I knew we would be on the Atlantic side that night. We went over mainly to see some of the canal from the train and to eat and drink at the Washington in Colon. .. 

Infrared is described as the range of frequency lying between visible light and very short wave radio. All materials and bodies unavoidably radiate infrared energy provided their temperature is above absolute zero. Infrared possibilities have been known for a number of years, although its development was delayed by radar. The first infrared aircraft detection system was perfected shortly following World War I. 

The free electrons in the ionosphere will reflect short wave radio waves at frequencies below their plasma frequency ( 50 MHz) but will transmit FM and TV frequencies. Spacecraft reentry creates a plasma whose frequency is much higher than that of the atmosphere, which accounts for the communication blackout during this phase of a space mission. 

GAF Carbonyl Iron Powders. Trademark of General Aniline and Film Corp, 435 Hudson St, New York, 10014, for microscopic almost perfect spheres of very pure iron (99 6 99.9% Fe). They are produced in eleven carefully controlled grades ranging in particle size from 3 to 20 microns in diam. Used in high frequency cores for radio, telephone, television, short wave transmitters, radar receivers and direction finders. Also used... 

Use High-frequency cores for radio, telephone, television, short-wave transmitters, radar receivers, direction finders alloying agents catalysts powder metallurgy magnetic fluids. 

Fourier transform Technique in which a short powerful radio-frequency pulse (microseconds) excites either all the nuclei or nuclei simultaneously. Each nucleus shows a free induction decay (FID) which is an exponentially decaying sine wave with a frequency equal to the difference between the applied frequency and the resonance frequency for that nucleus. 

The frequency range of short radio waves overlaps with that of long wave microwaves — from about 1 m to about 100 pm. Microwaves are of high technical importance. They cover the radar frequencies and the frequencies at which cellular (mobile) telephones work. Their impacts on food colorants, foods, and biological materials are similar to those of radio waves but the warming effect is more distinct. If microwave use is limited to the topics discussed in this book, no precautions are necessary. 

After the pulse, we wait for a short whilst (typically a few microseconds), to let that powerful pulse ebb away, and then start to acquire the radio frequency signals emitted from the sample. This exhibits itself as a number of decaying cosine waves. We term this pattern the free induction decay or FID (Figure 1.3). 

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