1/4 wavelength calculation and antenna length - RC Groups
Jul 05, 2007, 08:30 AM
Chuck 'Em and Chase 'Em
Discussion

# 1/4 wavelength calculation and antenna length

Guys,

I was looking to determine what length my broken antenna should be (since I did not measure it before hand and the manufacturer has given me a range of lengths to work with).

I noticed that somewhere it was said the the median 1/4 wavelength is 39.75 inches which should be for about channel 36 plus or minus.

When I did the following calculation (knowing that speed of light = wavelength x freq -> c/freq = wavelength)

I did the following :

299,792,458 metres per second /freq(Hz) = meters * (100cm/ 1m) *(1in/ 2.54cm) to get the wavelength in inches * 1/4 = 1/4 wavelength in inches

ex ch 30 = 72.390 mHz = 72,390,000Hz

299792458 / 72,390,000 *100 /2.54 * 1/4 ~ 40.76 inches

channel 36 should be about 40.69 inches

why is this wavelength LONGER than what it is stated to be for the median 1/4 wavelength?
Based on this equation, ch 55 is ~ 40.48 inches

Can anyone tell me where I went wrong???

Thanks
Frank
Last edited by Fly2High; Jul 05, 2007 at 08:43 AM.