One-Way communication

[nath88nael]

what makes a metal capable of receiving radio waves?

 

or to rephrase: what is the basic principle behind a functioning antenna?

[njaohnt]

what makes a metal capable of receiving radio waves?

 

or to rephrase: what is the basic principle behind a functioning antenna?

Medal that is half the wave length of the wave or more.

Here are medals that can be used from: http://www.ehow.com/list_6391717_types-metal-used-radio-antennas.html

1. 
   Copper
   
   • There are two types of copper antennas: solid and stranded. Solid copper antennas are made of a thick strand of pure copper or a copper alloy, such as hard-drawn copper-weld or copper clad with steel. Solid copper antennas are made from a single piece of copper wire and are commonly used in household electrical equipment wiring. Stranded antennas are made by twisting two or more solid wires around each other. The number of comprising wires determines the flexibility of the antenna. Types of copper-based antennas include 18 AWG (American Wire Gauge) copper clad steel, 14 AWG copper clad steel, 12 AWG copper clad steel, 16 AWG copper clad steel and 14 AWG antenna wire.

Galvanized Steel

• Galvanized steel radio antennas are made of steel coated with an additional layer of zinc that prevents the antenna from rusting, or oxidizing. Antennas made with galvanized steel can function in the harshest weather conditions and are designed to last many years. They require little maintenance.

Aluminum Tubing

• Aluminum tubing is typically used to make Yagi antennas. A Yagi antenna. or Yagi-Uda antenna, is found on rooftops to amplify television signals. It is used between 30 megahertz and 3-gigahertz frequencies. Yagi antennas are made of three elements: the directors, the reflectors and the driving element. Aluminum tubing of all sizes and thicknesses are used to make these components. Examples of aluminum Yagi antenna patterns include the 2 element Yagi, 3 element Yagi, 4 element Yagi and 5 element Yagi. Aluminum antennas are strong, lightweight and durable.
   
  Do you need any more info?

[nath88nael]

yes, i do have many questions on the subject

 

primarily, how do i communicate the radio frequency (once received by the antenna) to a speaker?

when does it become sound?

 

 

(and thanks for the link, you've jogged my memory a bit to a an example of a rudimentary two-way radio, and it's helped in my understanding of the topic)

[John Cuthber]

Does this help at all?

http://en.wikipedia.org/wiki/Crystal_radio

It's the simplest way to get sound from a radio signal.

[swansont]

yes, i do have many questions on the subject

 

primarily, how do i communicate the radio frequency (once received by the antenna) to a speaker?

when does it become sound?

 

 

(and thanks for the link, you've jogged my memory a bit to a an example of a rudimentary two-way radio, and it's helped in my understanding of the topic)

 

You don't communicate the radio frequency, you communicate the modulation of the frequency, be it modulation of the amplitude or the frequency. The RF itself is much too high a frequency to be heard — a MHz or more. You send that signal to a transducer, which changes the electrical signal into motion, in this case of a diaphragm in a speaker.

[njaohnt]

yes, i do have many questions on the subject

 

primarily, how do i communicate the radio frequency (once received by the antenna) to a speaker?

when does it become sound?

 

 

(and thanks for the link, you've jogged my memory a bit to a an example of a rudimentary two-way radio, and it's helped in my understanding of the topic)

 

You really should Google this stuff up. I'll only tell you what I know, so for everything else, I go look it up.

For a simple earphone, just simply connect it to the antenna, but you may need to use a transistor, or a relay to get it out the loudspeaker. It becomes sound when it gets to the loudspeaker.

 

When the frequency changes by just a bit, it causes a different amount of energy to travel through, so that you can communicate in code.

Edited January 4, 2012 by njaohnt