Micro Modellerde Anten Kablosu Kablosu Nasıl olmalıdır?
Rcgroupstan ibcrazy nickli alex biraderin -ki kendisi bir fpv ustadidir- paylasimidir.
"Building the antenna - Calculating your quarter wavelength
Building the antenna - Calculating your quarter wavelength
The first step in building any antenna is to calculate your effective wavelength. Many of us know the old formula: 2.98 * frequency in MHz = Wavelength in meters. This is the wavelength of a signal in free space, however we are interested in the wavelength in our transmitters. Thus we must include a “velocity factor”, which is usually around 95% of the actual calculated quarter wavelength in free space.
Everything can be determined based on a quarter wave antenna. I highly suggest using the exact frequency you plan to transmit. Why? Varying from the frequency causes antenna mismatch resulting in reduced VSWR! This is why the store bought antennas aren’t always the best match. They are made for a small range of frequencies.
Below are the formulas to calculate your active quarter wave assuming a 95% velocity factor:
Length in Inches (for 22AWG wire) = 2808/frequency in MHz
Or for you metric folks:
Length in Centimeters = 7125/ frequency in MHz
Or for 12-14 AWG:
Length in inches = 2750/f in MHz
Or on Centimeters = 6985/f in MHz
Alternately, you could go to any of these sites:
Bu LİNKİ görmek için izniniz yok. Giriş yap veya üye ol
Bu LİNKİ görmek için izniniz yok. Giriş yap veya üye ol
Bu LİNKİ görmek için izniniz yok. Giriş yap veya üye ol
Thus for my 910 MHz system, my quarter wave is 3.086 inches or 7.84 centimeters.
Note: In all of the antennas designed this number will be the length of the ACTIVE part of the antenna. The length inside the coaxial line or inside the coupler is not considered active. It is active once the conductor leaves the shielding."
2.4ghz icin 22awg kablo kullanilirsa
7125/2400=2.97cm tabi bu hesap tam olarak 2400mhz yani 2.4ghz icin gecerli. Farkli firmalar farkli frekans araliklarinda sistemler kullaniyor ama ortalama budur.