- published: 16 Mar 2013
- views: 11957
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 MHz to 300 MHz, with corresponding wavelengths of ten to one meters. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).
Common uses for VHF are FM radio broadcasting, television broadcasting, two way land mobile radio systems (emergency, business, private use and military), long range data communication up to several tens of kilometres with radio modems, amateur radio, and marine communications. Air traffic control communications and air navigation systems (e.g. VOR, DME & ILS) work at distances of 100 kilometres or more to aircraft at cruising altitude.
VHF was used for analog television stations in the US, and continues to be used for digital television.
VHF propagation characteristics are suited for short-distance terrestrial communication, with a range generally somewhat farther than line-of-sight from the transmitter (see formula below).
Basic VHF and UHF Fundamentals Antennas are a very important component of communication systems. By definition, an antenna is a device used to transform an RF signal, traveling on a conductor, into an electromagnetic wave in free space. Antennas demonstrate a property known as reciprocity, which means that an antenna will maintain the same characteristics regardless if it is transmitting or receiving. Most antennas are resonant devices, which operate efficiently over a relatively narrow frequency band. An antenna must be tuned to the same frequency band of the radio system to which it is connected, otherwise the reception and the transmission will be impaired. When a signal is fed into an antenna, the antenna will emit radiation distributed in space in a certain way. A graphical representa...
An introduction of how to turn on, set and use a VHF radio. Lesson provided by Mike Whitehouse, senior sailing instructor with the Canadian Yachting Association.
http://features.boats.com/boat-content/2013/05/video-how-to-use-a-vhf/ For more videos, visit www.boats.com. Your VHF radio is your lifeline to the outside world in case of emergency. So you gotta make sure you're using it right. The first thing you'll need to do is adjust the squelch. This is pretty simple: just turn it until it hisses, and then back it off until the hissing stops. That will eliminate all the unnecessary static. Tune to the channel you want, and then take the microphone and hold it at a 90 degree angle to your face. Speak slowly and clearly as you key the mike. Okay, now, let's make sure the radio's working properly by doing a radio check. First, tune to a station that's an open frequency, like channel 68. Then repeat three times, "Radio check, radio check, radio che...
Routine voice call using a Marine VHF DSC radio http://www.seavoice-training.co.uk/
American Canoe Association instructor and frequent Kayak Angler contributor Jeff Herman, has spent his life learning to keep paddlers and anglers safe on the water. Use his tips to use a marine VHF radio, which could one day save your life. For more videos, how to articles, kayak fishing skills and gear reviews, check out Kayak Angler's website, http://www.rapidmedia.com/kayak-fishing.html
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Lately I've been thinking that I don't feel like I used to do.
I'm trying to keep my two feet on the ground.
Constantly surrounded everywhere I turn I'm hounded,
people stop and stare and look me up and down.
Now you shouldn't feel down from what everybody says
and don't let it bother you if anybody stares,
'cause you know that at times people can be cruel,
try to put you down make you feel like a fool.
But you got one shot now don't you ever stop,
keep your dreams high keep reachin' for the top,
'cause you know and I know if they had the chance
they'd be climbin' up on the stage trying to dance.
CHORUS
C'mon C'mon and get together.
Lets take a chance, it's now or never,
spread the word over the nation
that we are the new generation.
C'mon C'mon and get together.
Start living your life like it's forever.
Don't wanna stop if you're dreamin',
let everybody know what you're feeling.
Questions I can't answer got me going round in circles.
Make me feel as though I'm losing self control.
It's feeling like a dream to me. I've lost a touch of reality
deep inside I've searched with my soul.
Now it's good to keep searching and bettering yourself
but don't push too hard 'cause it's bad for your health.
And running round in circles will always get you dizzy.
And thinking too much that will make your head busy,
so just sit back and relax, you gotta chill.
I promise that all of your dreams will be fulfilled.
One day if you keep on looking you'll find,
you just gotta go with your heart and your mind.
CHORUS x6