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+---- Thread: Understanding Comms Episode 2. (/showthread.php?tid=5985)
Understanding Comms Episode 2. - Scythe13 - 16 September 2013
Welcome back. I'm glad the first episode was more interesting than Easternders, and you've come back for a second session.
We'll be covering Frequency in this episode.
So, first off, we'll debunk some of that Tech-Jargon-Slang-Complicated stuff. Today we'll be looking at 2 'basic' terms.
VHF - Very High Frequency
UHF - Ultra High Frequency
What do they actually mean? Not important for now. We'll come back to these later.
Okay, Episode 2:
Remember last episode we spoke about the 5 parts of a radio connected by a battery? Good. We'll be working on the middle part of that today. The transmitter==>ariel==>ariel==>receiver part of the diagram.
When the transmitter gets the signal from your voice, it converts your voice to a frequency. WOOOOHH!!! What's a frequency?!?!? The thing is, you don't need to know. Check out the electromagnetic spectrum on google if you really want to, but that's too much effort for this beginners program. You just need to know it's a variation of a set of numbers. Over simplification, but that's okay.
The best way to think of a frequency is to think of a rainbow. A rainbow is a vast spectrum of different colours. Each colour nicely blends into the next, so they are all connected; purple blends into blue, blue into green, green into yellow, etc. So, for the sake of making comms frequency simpler, the transmitter changes your voice to colour frequency.
So, the radio changes your voice into, let's say, a yellow signal. Then, only radios whose receivers are set up to pick up yellow signals can hear your voice.
SD has a yellow transmitter and receiver radio. Highlander has a yellow transmitter and receiver radio. Beardyman has a blue transmitter and receiver radio.
If SD sends a message, Highlander will be able to hear him. But because Beardyman's radio is not the same frequency as HL's and SD's, he will not hear him. SD is sending a yellow signal, and Beardyman has a blue tuned radio. Silly Beardyman.
But what about if Beardyman wants to send a message? Now, the fun begins, when Beardyman uses his radio, it sends a blue signal (frequency). Neither SD nor HL can hear it, because they both have their radios set for Yellow signals (frequency). Beardyman is talking to himself.
You have to send (transmit) a signal at the same colour (frequency) the colour (frequency) that the other person is receiving on.
That is the basic explanation of frequencies. Just think, colours on a rainbow. If you send the wrong colour, then you will not be heard. Also, if you're set to pick up the wrong colour, you'll hear nothing.
So, UHF and VHF are just different rainbows.
A red UHF colour is from a different rainbow, so a person with a red VHF cannot hear or speak to the red UHF. They may be using the same colour, but they are using different rainbows.
Imagine a rainbow from a garden sprinkler system. That's VHF. A rainbow caused by rain is the UHF. The two are not the same rainbows, even though they have the same colours. You need the same rainbow and colour to be able to communicate to one another.
I hope that makes sense. If not, as usual, message me with any questions. We'll get more into frequency later, but once you understand how a radio works, that's when we'll go more complicated. If you can understand this, you can understand about 75% of radio communications.
RE: Understanding Comms Episode 2. - I-K-E - 16 September 2013
I got a better understanding of frequency due to my education but for a simplification that's a good way of doing it
nice job!
RE: Understanding Comms Episode 2. - Grumpy Grandpa - 16 September 2013
That's definitely not the way my instructors in Aldershot explained it to us all those years ago - but I get your drift. Keep drifting...
RE: Understanding Comms Episode 2. - Scythe13 - 16 September 2013
Unless you know about frequencies, this is the easiest way to explain it, that I could think of, without going into too much maths.
Like I said in my "Do you want a mini series" thread, as long as you get how it works, and how to make it down, you don't need to know the fine detail. Like a microwave. We all know that it uses radiation, or something like that, to heat up our food. Just press a few buttons, and bing, out comes a hot meal. You don't need to understand magnetrons and the alike to work a microwave.
So this is a (probably overly) simplified intro to comms.
RE: Understanding Comms Episode 2. - Grumpy Grandpa - 17 September 2013
I get it - it's good. Keep it coming...