two cell antenna delta for 40 meters

The first figure shows a conventional antenna Delta with dimensions for a range of 40 meters. The size of the delta can be calculated by the formula L = 304 / F: L - perimeter of the delta, F - frequency at which it is set. At the point of connection of the coaxial cable included tuning loop length of 80 centimeters. Setting the delta is produced by this train on a minimum SWR. The antenna radiates perpendicularly to the antenna plane. Increase the gain of the delta can be placed at a distance L / 4 from the existing framework of another of the same frame of the same length. Delta gain increases due to the fact that one performs the role of the delta frame vibrator and the other reflector (second figure), i.e. the antenna is unidirectional. In order to change the direction of emission of the delta to the framework necessary to connect an additional antenna loop length L / 4 from the same coaxial cable, and set the switch (third picture). Cable length of frames to loop can be arbitrary. This antenna system can operate only on one range. Strengthening the double delta of about 7 dB. For a more exact matching antenna tuner is needed.

The distance between the borders of the delta in meters:

28 MHz - 2.65

21 MHz - 3.54

14 MHz - 5.32

7 MHz - 10.64

3.6 MHz - 20.2

Loop length in meters:

28 MHz - 1.75

21 MHz - 2.34

14 MHz - 3.52

7 MHz - 7.02

3.6 MHz - 13.33

(Dimensions loop length for the cable impedance of 75 ohms for the other cables needed and stored in the velocity factor.)

Space Solar Power

The United States and the world need to find new sources of clean energy. Space Solar Power gathers energy from sunlight in space and transmits it wirelessly to Earth. Space solar power can solve our energy and greenhouse gas emissions problems. Not just help, not just take a step in the right direction, but solve. Space solar power can provide large quantities of energy to each and every person on Earth with very little environmental impact.

The solar energy available in space is literally billions of times greater than we use today. The lifetime of the sun is an estimated 4-5 billion years, making space solar power a truly long-term energy solution. As Earth receives only one part in 2.3 billion of the Sun's output, space solar power is by far the largest potential energy source available, dwarfing all others combined. Solar energy is routinely used on nearly all spacecraft today. This technology on a larger scale, combined with already demonstrated wireless power transmission (see 2-minute video of demo), can supply nearly all the electrical needs of our planet.

Another need is to move away from fossil fuels for our transportation system. While electricity powers few vehicles today, hybrids will soon evolve into plug-in hybrids which can use electric energy from the grid. As batteries, super-capacitors, and fuel cells improve, the gasoline engine will gradually play a smaller and smaller role in transportation — but only if we can generate the enormous quantities of electrical energy we need. It doesn't help to remove fossil fuels from vehicles if you just turn around and use fossil fuels again to generate the electricity to power those vehicles. Space solar power can provide the needed clean power for any future electric transportation system.

While all viable energy options should be pursued with vigor, space solar power has a number of substantial advantages over other energy sources.

Advantages of Space Solar Power

• Unlike oil, gas, ethanol, and coal plants, space solar power does not emit greenhouse gases.

• Unlike coal and nuclear plants, space solar power does not compete for or depend upon increasingly scarce fresh water resources.

• Unlike bio-ethanol or bio-diesel, space solar power does not compete for increasingly valuable farm land or depend on natural-gas-derived fertilizer. Food can continue to be a major export instead of a fuel provider.

• Unlike nuclear power plants, space solar power will not produce hazardous waste, which needs to be stored and guarded for hundreds of years.

• Unlike terrestrial solar and wind power plants, space solar power is available 24 hours a day, 7 days a week, in huge quantities. It works regardless of cloud cover, daylight, or wind speed.

• Unlike nuclear power plants, space solar power does not provide easy targets for terrorists.

• Unlike coal and nuclear fuels, space solar power does not require environmentally problematic mining operations.

• Space solar power will provide true energy independence for the nations that develop it, eliminating a major source of national competition for limited Earth-based energy resources.

• Space solar power will not require dependence on unstable or hostile foreign oil providers to meet energy needs, enabling us to expend resources in other ways.

• Space solar power can be exported to virtually any place in the world, and its energy can be converted for local needs — such as manufacture of methanol for use in places like rural India where there are no electric power grids. Space solar power can also be used for desalination of sea water.

• Space solar power can take advantage of our current and historic investment in aerospace expertise to expand employment opportunities in solving the difficult problems of energy security and climate change.

• Space solar power can provide a market large enough to develop the low-cost space transportation system that is required for its deployment. This, in turn, will also bring the resources of the solar system within economic reach.

Disadvantages of Space Solar Power

• High development cost. Yes, space solar power development costs will be very large, although much smaller than American military presence in the Persian Gulf or the costs of global warming, climate change, or carbon sequestration. The cost of space solar power development always needs to be compared to the cost of not developing space solar power.

Requirements for Space Solar Power

The technologies and infrastructure required to make space solar power feasible include:

• Low-cost, environmentally-friendly launch vehicles. Current launch vehicles are too expensive, and at high launch rates may pose atmospheric pollution problems of their own. Cheaper, cleaner launch vehicles are needed.

• Large scale in-orbit construction and operations. To gather massive quantities of energy, solar power satellites must be large, far larger than the International Space Station (ISS), the largest spacecraft built to date. Fortunately, solar power satellites will be simpler than the ISS as they will consist of many identical parts.

• Power transmission. A relatively small effort is also necessary to assess how to best transmit power from satellites to the Earth’s surface with minimal environmental impact.

All of these technologies are reasonably near-term and have multiple attractive approaches. However, a great deal of work is needed to bring them to practical fruition. In the longer term, with sufficient investments in space infrastructure, space solar power can be built from materials from space. The full environmental benefits of space solar power derive from doing most of the work outside of Earth's biosphere. With materials extraction from the Moon or near-Earth asteroids, and space-based manufacture of components, space solar power would have essentially zero terrestrial environmental impact. Only the energy receivers need be built on Earth. Source: www.nss.org 

Ham Radios in Space

NASA's Space Amateur Radio Experiment is connecting students and ham radio operators on Earth with astronauts in Earth orbit.

U.S. Astronaut Owen K. Garriott - W5LFL

For most amateur radio operators, it is the thrill of a lifetime to receive a "CQ", or general call, from an astronaut in space. But for some, like former astronaut Dr. Owen K. Garriott, call sign W5LFL, the thrill comes from receiving a response from "hams" down on Earth.

Garriott, who has been an amateur radio operator for over 40 years, was the first astronaut to take a ham radio into space, pioneering the way for an increasingly well developed amateur radio space program.
 

"It was my good fortune to take the first amateur radio into space on STS-9 in November 1983," Garriott said. "In my spare time only, I managed to hold up an antenna to the window and to talk to amateurs on Earth."

This contact was the first communication between astronauts and people on the ground outside of "official" channels, which are usually reserved for presidents and heads of state.

Owen Garriott pioneered the use of ham radio from Earth orbit during his "spare time" on shuttle flight STS-9. Now, the Space Shuttle frequently carries amateur radio equipment into space where astronauts communicate with students on Earth below.
 

Hams, as amateur radio operators are often called, use radio transmitters and receivers to talk to other hams all over the globe, as well as to those in space. There are more than 1.5 million licensed hams worldwide, including more than 400,000 Americans.

Every radio amateur must be licensed by the Federal Communications Commission (FCC). In order to obtain a license, a ham must pass an examination, which includes questions about radio theory, rules and regulations. There are three grades of licenses, each at progressively higher levels of proficiency: Technician, General and Amateur Extra. Any licensed ham can chat with the Shuttle.

Once the examination is passed, the FCC issues the amateur operator's call letters. The first letter indicates nationality. In the United States, the first letters are A, K, N, or W.

Garriott had originally proposed the idea of taking a ham radio into space on his first space mission, Skylab 3, but was unable to due to timing and other complications. Ultimately, though, he persisted and was able to obtain permission to fly a small hand-held transmitter/receiver aboard the Space Shuttle Columbia

 

This is U.S. Astronaut Owen K. Garriott - W5LFL - aboard the U

.S. Space Shuttle Columbia STS-9. He is holding a Motorola two meter FM ham radio.

"When in orbit over land, I could make a CQ, which is a general call, and see who responded," Garriott said. "I used a well-designed, hand-held antenna, known as a 'cavity antenna', which could be velcroed to the window. It was about 24 inches in diameter and looked somewhat like a large aluminum cake pan. The transceiver then connected to the antenna."

  

In addition to the general calls, Garriott had made a few plans to send out a call to specific Earth-bound hams at prearranged times and dates."I had specified particular times and frequencies beforehand," Garriott said. "Among others, I was able to speak with the Amateur Radio Club in my hometown of Enid, Oklahoma, with my mom, with Senator Goldwater, and with King Hussein, who was an avid ham."

 

Since that first voyage into space, NASA has continued to see the usefulness of bringing ham radios into space, and astronauts have been able to speak to hams on earth on dozens of shuttle flights, as well as on the space station MIR. "There has been substantial amateur radio activity in space since I first brought one up," Garriott said. "There is now a program called SAREX that is allowing for more and more activity."

 

The Space Amateur Radio Experiment (SAREX) is a long-running program to use amateur radio equipment on board the Space Shuttle to involve students in exchanging questions and answers with astronauts in orbit. Students in hundreds of different classrooms across the country are able to ask the astronauts questions about space flight and the experiments being conducted on the mission. It also allows for communication with amateur radio operators on the ground.

 

SAREX is sponsored jointly by the American Radio Relay League (ARRL), the Radio Amateur Satellite Corporation (AMSAT) and NASA. Students and amateur radio operators can attempt to contact astronauts flying on a SAREX mission through voice, packet (computer) radio, or television, depending on what equipment is flying on the shuttle and on what equipment is available on the ground.

In addition, in 1997, NASA approved plans to include amateur radio equipment as part of the payload of the International Space Station (Amateur Radio on the International Space Station or ARISS). Since astronauts will have more time in space while on the ISS, more opportunities for ham radio contacts will exist. "Shannon Lucid used a ham radio while on MIR," said Garriott. "NASA saw how using an amateur radio would be a good thing for astronauts to do in their spare time on the space station."

 

Onboard the Space Shuttle Endeavour, astronaut Linda M. Godwin (right) talks to students (left) via the Shuttle Amateur Radio Experiment (SAREX). The payload commander, as well as several other STS-59 crew members spent some off-duty time using the amateur radio equipment to communicate with "hams" and students on Earth.

And certainly hams on the ground are eager for contact with the astronauts. Specially designed shuttle "QSL" cards, which are postcards used by hams to confirm two-way contact or reception of a signal, are among the most prized in a ham's collection -- even to a king.

"(King) Hussein regarded his 1983 contact with Owen Garriott, W5LFL, on board Space Shuttle Columbia, as a high point in his amateur radio career," reported ARRL Executive Vice President David Sumner in a special bulletin following the death of Jordan's King Hussein, JY1. ("JY1" was King Hussein's call sign.)

SMALL FM TRANSMITTER USING ONE TRANSISTOR

Hello friends this one is the simple and basic Fm transmitter circuit using one transistor specially for student  and Beginners who want to starts their the hobby of electronic.


 It is simple in construction and working . And all the circuit and component details are given in the above picture and the video will show you the working and the function the small range  fm transmitter . 

 

Please friend just take care about the CBE of the transistor as you may new in the electronic and dont get hopless when your circuit will not working in the first time try until you not get the success . because this circuit will required little hard work not much but little. so never leave it by just after soldering it ok .

   

And i upload a video for your reference so you can get some basic idea of the making of it. and if is not compulsory to make it on copper plate , you can make it on any type of PCB.

  

 If any one have query or problem in the making of the fm transmitter then you can contact me any time. 

The Monoband HF Dipole Antenna

If you're looking for an easy antenna for your favorite HF band, you can't go wrong with a half-wavelength dipole! All you need are three insulators (one is used as your center connector) and some wire. Strong, multistranded copper wire will withstand the elements best. The only trick to making a dipole is cutting it to the right length. A dipole antenna is made of two equal lengths of wire with the total length adding up to a half wavelength at the desired frequency.
 

Here are the required dipole lengths for each of the Novice/Technician HF sub bands:

80 meters: 126' 6"
40 meters: 65' 7" 15 meters: 22' 1"
10 meters: 16' 6"
 

For example, if you're making a dipole for the 10-meter band, you'll need two lengths of wire 8' 3" long (8' 3" x 2 16' 6") plus enough extra so the wire can be looped through the insulator and secured tightly. Attach the wires to the insulators and center connector as shown in Fig 1. Attach your coax feed line at the center connector.

Solder the shield braid of the coax to one side of your dipole. Solder the center conductor of the coax to the other side. Be careful not to melt the coax while you're soldering it to the antenna. You can also purchase center connectors that feature built-in SO-239 jacks.
 

With a matching PL-259 plug on your feed line, you can easily disconnect your feed line from your antenna whenever necessary for portable operation, for example. What-ever way you connect the coax to the antenna, be sure to waterproof the connection if it will be outdoors. If water gets inside the cable its loss will increase in a hurry!

 

 

So, what type of coaxial cable should you use? If the distance from your transceiver to your dipole is less than 50 feet or so, RG-58 is fine. For longer runs, I'd strongly recommend a low-loss cable such as RG-8, RG-213 or Belden 8214. If you own an antenna tuner, you can try feeding your dipole with 450-Q ladder line. This type of open-wire feed line exhibits very low loss at HF.

  

Choose your antenna supports: trees, flagpoles, chimneys or whatever stirs your imagination. You can even install your dipole in an attic. If you decide to mount it outdoors, invest in enough high-strength rope or cord to do the job. You want to be sure your antenna will survive storms, ice loading and so on. Mount your dipole as high off the ground as possible. How high is "high?" Conventional wisdom states that your dipole should be mounted at least a quarter wavelength above the earth at the frequency you choose to operate.

  

Getting an 80-meter dipole 60 feet off the ground could present a challenge! If you can't raise your dipole to this altitude, don't worry about it! Your performance may suffer a bit, but the antenna will work. Watch out for nearby gutters, pipes, aluminum siding, window screens and other large pieces of metal. They'll detune your dipole and increase the SWR if they're too close. And, of course, never place your antenna near power lines!

If you've cut your dipole to the proper length, your SWR should be reasonably low (less than 2:1). Don't worry if the SWR seems to rise as you move in frequency toward the band edges—this is normal.

  

Of course, the dipole you've just designed is good for only one band, right? Well.  not necessarily! If you own an antenna tuner, try using it to load your transmitter on other  bands.

The SWR will be very high, but your tuner may be able to adjust it down to a flat 1:1 match. This won't do a thing for the actual SWR on the feed line, but if you've invested in low-loss cable or ladder line, it doesn't matter! Are you surprised to hear this? Many hams, even veterans, are slaves to the idea that only a 1:1 feed line SWR is acceptable. If your feed line is very "lossy," this is true.

  

If you invest in low-loss feed line, however, only a small portion of your signal is actually lost due to high SWR. The rest of it is radiated by your antenna. So if you've designed your antenna for, say, the 40- meter band, try it on other bands as well. You may find that your monoband dipole is really a multiband antenna!