Ads
related to: best length for wire antenna- Amazon Deals
New deals, every day. Shop our Deal
of the Day, Lightning Deals & more.
- Amazon Prime Benefits
Get Free Delivery, Exclusive deals
Popular TV, Movies & So Much More!
- Wearable Technology
Discover the Best Wearable Tech
Smartwatches, Glasses & Accessories
- Alexa Built-in Devices
Deals On Alexa Built-in Devices
Instantly Connect to Music and News
- Amazon Deals
Search results
Results From The WOW.Com Content Network
Often random wire antennas are also (inaccurately) referred to as long-wire antennas.There is no accepted minimum size, but actual long-wire antennas must be greater than at least a quarter-wavelength ( 1 / 4 λ) or perhaps greater than a half ( 1 / 2 λ) at the frequency the long wire antenna is used for, and even a half-wave may only be considered "long-ish" rather than "truly ...
Assuming the building is about 20 feet tall, the length of wire seems to be on the order of 100 feet long – too short to be an HF Beverage antenna. Random wire antenna Moxon (1993) describes the random-wire antenna as an "odd bit of wire". [14] [page needed] It is the typical informal antenna erected for receiving shortwave and AM radio.
The electrical length of an antenna, like a transmission line, is its length in wavelengths of the current on the antenna at the operating frequency. [ 1 ] [ 12 ] [ 13 ] [ 4 ] : p.91–104 An antenna's resonant frequency , radiation pattern , and driving point impedance depend not on its physical length but on its electrical length. [ 14 ]
In antennas built for frequencies near or below 600 kHz [b], the length of an antenna's wire segments is usually shorter than a quarter wavelength [c] [ 1 / 4 λ ≈ 125 m (410 feet) [c] at 600 kHz [b]], the shortest length of unloaded straight wire that achieves resonance. [5]
Often called “Windom” antennas – By carefully selecting the feedpoint position at about 1 / 3 of the length of a half-wavelength wire, its feedpoint impedance is nearly constant for a variety of nearly-harmonic frequencies of the half-wave frequency. All Windom-style antennas have wide coverage gaps in between their nearly ...
In transmitting antennas the impedance of the antenna must be matched to the feedline for maximum power transfer. A half wave whip antenna (length of ) has somewhat higher gain than a quarter wave whip, but it has a current node at its feedpoint at the base of the rod so it has very high input impedance. If it was infinitely thin the antenna ...