ANTENNA UHF

UHF ANTENNA

For sure the television reception in the range of decimeter waves, recommend using double spiral antenna, the production of which under force even to the beginner. With linear polarization, a sufficiently narrow radiation pattern (width of the lobe in the horizontal plane is less than 35°) and the gain is nearly equal to 22 dB, this device is more compact than the widely known multiple-element designs such as “wave channel”, a bandwidth significantly exceeds them!

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UNIVERSAL BATTERY

UNIVERSAL BATTERY

At work and in everyday life there is often a need in galvanic power source with a stepped gradation of the EMF (including the symmetric polar voltage). Often this “standard” range: ±1.5 to 12 V. In such cases it is highly useful is a homemade cassette, which allows you to quickly assemble a battery of two, four, six or eight galvanic elements 373 (“Mars”, “Orion”).

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VIBRATE

VIBRATE

If you were in a situation when you need to put expensive stuff on display, but to ensure its safety without attracting the attention of people even when triggered the alarm. Or, for example, you need to Wake up early, but not to disturb the household. This is especially true when in the same room with their parents children sleep. For this fit, we offer vibrating alarm. You can make yourself using simple electric circuit and the miniature motor with an eccentric, taken from old, obsolete cell phone.

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THE TREE WAS LIT

THAT THE CHRISTMAS TREE IS LIT

Rosli new year holidays. Very pleasing to the eye colorful lights of garlands on the Christmas tree. However, the “old new year” series of light bulbs in garlands of Chinese production had thinned out considerably. After the holidays I had garlands to fix. I think that this problem might have many. So will share his experience in this matter.

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FIREPLACE FOR BEES

FIREPLACE FOR BEESResearch scientists and experience of beekeepers show that with a good supply of benign feed and caring the contents of a winged honey bee plants can stand the winter even when severe frosts. After all trouble for weakened bee colonies in the cold season is not so much the reduced temperature, how much humidity, when the frames and the inner surface of hives moldy, and the increase of the thermal conductivity of moist air surrounding a ball of bees, and damp walls threatens to increase in heat loss with all the ensuing grave consequences.

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HOT TIN

HOT TIN

Heater mini type electric air heater (IEC) is now unlikely to surprise anyone. To acquire these small and comfortable appliances for every taste. But it is not necessary to spend money on industrial products, especially imported. I, for example, has long been home-made and, according to the unanimous confession of the household, very aesthetic of MEK.

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IMPROVED PROBE

IMPROVED PROBE

Primitive “control print” — electroputere with two wires and the lamp — not the best device for “continuity” of electric circuits. Commercially available testers and isometry is also called a gift, especially when you have to deal with modern technology, and they are not cheap. So we have electricians to create probes-indicators — versatile, compact and reliable. On one of these devices tell the magazine “modelist-Konstruktor” No. 5 for the year 1990.

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WHEN THE TENSION IS GONE

WHEN THE TENSION IS GONE

Many of the houses in the villages and country houses in winter, left without owners, are empty, although things are (sometimes valuable) and appliances remain in them. And then waiting for the owners the risk of theft, so they prudently put in a house alarm is usually powered from a household outlet of 220 V. But in rural areas quite often happens, especially in bad weather, gusts of wind that the voltage in the lighting network “disappears”.

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CONVENIENT SOLDERING IRON

CONVENIENT SOLDERING IRONThe soldering iron is any homebrew. But those who have to deal with modern electro – and radio equipment, this tool is something special. And the requirements for it are quite hard: with small size, low supply voltage and low power consumption to ensure the excellent quality of soldering. And with the maximum comfort, including temperature controller soldering tip and a stand with a tray under flux solder and tinning.

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ULTRASOUND AGAINST RODENTS

ULTRASOUND AGAINST RODENTS

Among the elastic vibrations of the air special interest to long causes imperceptible to the human ear ultrasound (from Latin ultra, next, over, beyond), the lower frequency limit of which is considered to be 20 kHz. Insects, bats and even cetaceans have successfully used this natural gift: some are for communication, others for hunting, others for the locations of terrain and obstacle avoidance in poor visibility conditions.

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