FM antenna design?

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Mar 27, 2005 | 11:11 AM

#16

Bob Ayers

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From: Durham, NC

Quote:

Originally Posted by FghtinIrshNvrDie

to determine how long you need your antenna, you need to find the amplitude of the signals. from wave crest to valley. Not wavelength...

Not true, the length of the antenna is determined by the frequency, which determines the wavelength. The higher the frequency, the lower the wavelength, the shorter the antenna.

Mar 27, 2005 | 11:22 AM

#17

FghtinIrshNvrDie

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From: Pleasant Hill, MO

that's true. frequency and wavelength are inversely proportional. They all travel at the same speed. The waves from the tower travel in a straight line to your antenna. The wave will hit it horizontally. I still say that the amplitude (height) of the wave is what should determine your antenna height.

Ryan

Mar 27, 2005 | 12:31 PM

#18

Bob Ayers

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Joined: Jan 2003

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From: Durham, NC

Quote:

Originally Posted by FghtinIrshNvrDie

Sorry to flame you, but your wrong!! If antenna length was based on amplitude, AM would never work!!! And, the closer you were to the transmitter site, the longer antenna you would need, and if you were a long way from the transmitter, you wouldn't need an antenna at all!!

Just curious, where did you get this idea at? What is your theory on the transmitter antenna length? The higher power the longer antenna??

Last edited by Bob Ayers; Mar 27, 2005 at 12:43 PM.

Mar 27, 2005 | 04:49 PM

#19

groundrat

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Joined: Jan 2002

Posts: 630

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From: New Hampshire

http://www.crompton.com/wa3dsp/hamradio/antcalc.html

http://www.rvwars.com/antenna.html

http://www.csgnetwork.com/antennaedcalc.html

Try some of these. I work in Ground Radio Maintenance in the U.S Air Force and could probably bore you all to death with antenna theory, propagation, and the like. Have fun all!