- published: 04 Nov 2007
- views: 175180
Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF). The frequency allocation is done by ITU.
These names referring to high-end frequency usage originate from mid-20th century, when regular radio service used MF, Medium Frequencies, better known as "AM" in USA, below the HF. Currently VHF is at the low-end of practical frequency usage, new systems tending to use frequencies in SHF and EHF above the UHF range. See Radio spectrum for full picture.
Common uses for VHF are FM radio broadcast, television broadcast, land mobile stations (emergency, business, private use and military), long range data communication with radio modems, amateur radio, marine communications, air traffic control communications and air navigation systems (e.g. VOR, DME & ILS).
VHF propagation characteristics are ideal for short-distance terrestrial communication, with a range generally somewhat farther than line-of-sight from the transmitter (see formula below). Unlike high frequencies (HF), the ionosphere does not usually reflect VHF radio and thus transmissions are restricted to the local area (and don't interfere with transmissions thousands of kilometres away). VHF is also less affected by atmospheric noise and interference from electrical equipment than lower frequencies. Whilst it is more easily blocked by land features than HF and lower frequencies, it is less affected by buildings and other less substantial objects than UHF frequencies.
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