Category: Devices

How to Buy a TV AntennaHow to Buy a TV Antenna

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It is one thing to own a TV set, but it is different altogether to receive the channels you want to watch. You need to install a TV antenna to receive the channels available in your area.  Besides, you get to save on paying for Pay-TV stations because you can access so many of over the air free channels with an antenna.

With so many types of antennas in the market, choosing the best one can be difficult. If you want less hassle, you can select an omnidirectional outdoor TV antenna.

Here are some of the considerations when buying a TV antenna:

Whether Indoor or Outdoor

tv with internal antennaYou need to decide if you will buy an internal or an external antenna. Internal antennas have their challenges because they do not perform well. This is due to the blocking of signals by the buildings’ walls and signal interference by reflections resulting from the building’s objects.

Some things that increase signal interference are fluorescent lights, electrical gadgets, and other things. Conversely, external antennas perform better in picking signals but cost more to install. People in high signal areas can rely on indoor TV antennas, but those in poor signal areas need outdoor antennas.

Whether for Terrestrial or Satellite Broadcasts

satelitte dishWhen buying an antenna, one of the initial decisions is whether the antenna is to be used for satellite (DBS) or terrestrial broadcasts.  Satellite broadcasts normally require dish antennas or parabolic reflectors, which have to be accurately aligned to the antenna and get signals from the satellite at frequencies ranging between 10.95GHZ and 12.75GHZ.

Various antennas are applicable for terrestrial transmission, which could be internal or external antenna in several forms. The terrestrial transmissions mostly operate on the UHF portion of the radio spectrum, but some are still running on the VHF spectrum portion in some countries. The vital thing is to have a specific satellite antenna for satellite transmissions and have a terrestrial antenna for terrestrial TV transmissions.

Antenna Type or Style

terrestrial antennaTerrestrial TV transmission has many antenna styles that can match it, the common one being Yagi or Yagi-Uda. For satellite transmission, the parabolic reflector style of the antenna is used. Another design is the log periodic antenna used where the TV stations are widely spaced in frequency, requiring a wide bandwidth.

The size and the gain should dictate the choice of the antenna style. Antenna styles that are physically too large may be complex to install and will be susceptible to damage by the wind; hence need more robust installation, which means more costs.


Breathalyzers – The importance of regular alcohol content testingBreathalyzers – The importance of regular alcohol content testing

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Introduction

It is no secret that many people enjoy drinking. However, most of them are unaware of how it affects their bodies and organs. Once ingested, alcohol will pass from your stomach directly into the small intestine. Here, it will be rapidly absorbed into the blood and subsequently distributed through the rest of the body. Since alcohol is distributed so thoroughly and quickly, it can substantially affect the central nervous system.

Drinks that have high concentrations of alcohol, such as vodka or whiskey, will enter your bloodstream much quicker when consumed on an empty stomach. What this means is that you will not get more intoxicated from the straight vodka or whiskey, however, you will start experiencing the effects of alcohol intoxication much faster.

Alcohol content in your blood and breath

Breathalyzers Once the alcohol is in your bloodstream, it will immediately start circulating through your body and generating the standard effects on the brain and body. As the blood passes through the body, it finally reaches the liver, where it gets gradually filtered out from the bloodstream. It will continue to reduce with each pass until the body is free of any traces of residual alcohol. Additionally, the alcohol will also pass through your lungs, which means that some of the alcohol content will evaporate into your lungs and the air you exhale.

To measure this content, you can use a Breathalyser, which is a small, handheld device used specifically for this purpose. When using this device, it is important to measure your “deep lung air,” as well as avoid drinking at least 20 minutes before the test.

Why should you wait?

If you use this device immediately after drinking, or few minutes after, you will blow all the remaining alcohol content in your mouth straight into the breathalyzer receiver. This will cause the device to read a far greater concentration than it would if you had waited at least 20 minutes. This period will allow the alcohol content to pass through your stomach, then through your bloodstream and finally into the exhaled air.

A device such as this can be very useful if you want to get a clearer picture of how well your organism absorbs alcohol. For that matter, it should be used numerous times over a certain period. Keep in mind that everyone is different and that various factors can influence the absorption of alcohol. Some of these factors include your metabolic rate, as well as the amount of food you have in your stomach when drinking.

How to use one?

If you want to get the most out of your personal breathalyzer, make sure to use it on a regular basis, so as to closely monitor any changes in your intoxication level. Also, do not forget to always wait at least 20 minutes after smoking or drinking, before you conduct the test.

To use this device properly, you should take a deep breath and deliver steady and consistent blows. Continue doing that until the device gives out a signal that you should stop. After that, wait a few seconds while the device measures your BAC (blood alcohol concentration).

Variable accuracy

man drinking Last, but not least, keep in mind that the accuracy of every sensor is measured under strict laboratory conditions, right after the calibration. In real life conditions, it is highly unlikely that the same level of accuracy will be obtained on a regular basis. Therefore, if you are using a personal breathalyzer, always take into account a certain margin of error, which usually depends on the type and quality of a sensor.