Home |
Search |
Today's Posts |
#1
|
|||
|
|||
General Exam Questions
Could someone please help me understand how this 1/2 wavelength and
1/4 wavelenght thing is measured?? I'm trying to get a handle on how to figure out what a wavelength is or how you measure one. Antenna height and so forth are all figured according to set formulas, right?? Thank you very much. |
#2
|
|||
|
|||
General Exam Questions
On Jan 4, 10:59*pm, "Brenda Ann" wrote:
wrote in message ... Could someone please help me understand how this 1/2 wavelength and 1/4 wavelenght thing is measured?? *I'm trying to get a handle on how to figure out what a wavelength is or how you measure one. *Antenna height and so forth are all figured according to set formulas, right?? Thank you very much. Wavelength (m) = 300/f Examples: 146 MHz (2m amateur) 300/146 = 2.05m (rounded to the nearest 100th) 10 MHz (WWV) 300/10 = 30m 440 MHz (70cm amateur) 300/440 = .068m (rounded to the nearest 1000th) To compute half wave in meters simply divide by 2 To compute quarter wave in meters simply divide by 4 For real world applications of antenna building, you would want to do the following: For a driven (active) element, multiply your result by .95 For a reflector element leave as is. For a director element, multiply your result by ~.90 These will not be precise, but they are practical, and do work well. Well, I'll be printing this e-mail out and putting it under my pillow at nite. THANK YOU VERY MUCH. Wish me luck. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
New General with dipole questions | Antenna | |||
Sony SW77 general questions | Shortwave | |||
Sony SW77 general questions | Shortwave | |||
BC250D General Questions | Scanner | |||
Are RF safety questions too hard for the proposed new Novice exam? | Policy |