The Wonderful World of Radio

What do you think of when you hear the word radio? Maybe you think of your local music station. Perhaps you think about picking up far away stations with your AM radio. You may also think of the walkie talkies you used as a kid. These are all great uses for radio but that's not all.

What Are Radios Used For?

Radio is all around you. Your cell phone, wifi, gps, microwave, walkie talkies, car radios, bluetooth speakers, etc. If your device doesn't have to be connected with a wire then you are using radio.

The Radio Spectrum

The radio spectrum refers to a set of frequencies from down near 1khz all the way up to 300ghz. On the low end you find things such as military, AM, and amateur radio. These radio frequencies are known as ELF (extremely low frequency), LF (low frequency), and HF (high frequency). These frequencies reflect off the upper atmosphere and return to earth allowing worldwide communication. The section above HF is called VHF (very high frequency). Here you will find your favorite music station for your drive to work, aircraft, amateur radio, railroads, businesses , boats, and TV. you read that right, your TV is nothing more than pictures sent over the radio. Above VHF comes UHF (ultra high frequency). Here you will find amateur radio, more businesses, cell phones, emergency services (think fire and EMS), etc. Above this point you get gps, wifi, satellite TV, microwaves, etc.

How Does My Microwave Cook Food Without Hurting me?

Good question. Your microwave uses nearly the same frequency as your home wifi. The difference is in power and shielding. Your microwave runs at ~700 watts of power. Your wifi router on the other hand runs at 1 watt or less. The microwave also traps the generated radio waves inside the compartment where your food is placed.

Modes, RDF And DX

radio modes are pretty simple. AM, FM, CW (morse code) and SSB (single side band) are all examples of radio modes. RDF (radio direction finding), also known as fox hunting, is trying to find where a radio signal is coming from. RDF can be used to find downed aircraft, locate someone in the woods, track down interference, or just for fun. Radio DX or simply DX is listening for a far away station to see if you can hear something. If you live in the US and hear a station from Europe, that's DX. getting antenna TV channels from far away is DX. Even hearing a weak signal in your car on a channel that is normally static is DX.

Analog, Digital, Scanners and the Future

Digital radio is here like it or not. Tv is digital, emergency services are going digital, amateur radio ops are going digital, even the radio stations you listen to in your car are going digital. A big reason is that digital takes up less spectrum. Think of beach front homes. There are only so many to go around. Once those are all full there are no more left for others. Digital radio makes every property a bit smaller but not to small and allows new homes to be built on the same beach. Digital radio also allows for encryption of radio signals. Analog radios can see a signal there but are unable to decrypt it to listen to the voice data. This is a source of argument between the public and cops for example.