making an antenna

[friedthat]

I was wondering; i have an old ducky that i took apart (unwound and ripped the plastic rubber off of it. Now if i want to make this long vertical wire for a specific band i.e 400-430Mhz should i use quarter wave calculation or half wave to cut it to length?

 

[Don_Burke]

Try a quarter wave first.

You can also try a coaxial antenna which would work pretty well at a total length of one half wave.

 

[friedthat]

so why would one be better at half wave and the other be better at 1/4 wave? ALSO what about distance. if the site is farther away i.e 20 miles or so which wavelength should i go with 1/2 1/4 or 5/8?

 

[hoser147]

Check out the WiKi antenna section there is a wealth of info on making al sorts of antenna's there..............Hoser

 

[Don_Burke]

so why would one be better at half wave and the other be better at 1/4 wave? ALSO what about distance. if the site is farther away i.e 20 miles or so which wavelength should i go with 1/2 1/4 or 5/8?

A coaxial antenna is two quarter wave elements that make up a half wave antenna.

For 20 miles, I would forget the duck and put something outside.