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Universal Beverage Antenna

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ANTENTOP- 01- 2015 # 019

Universal Beverage Antenna

 

 

Receiver/transmitter with the feedline is attached to one end and the other terminated through a resistor (300- 600 Ohm) to ground. The value of the resistor should be equal to the wave impedance of the transmission line that created by the antenna wire and the ground under the wire. So, optimum value of the resistor depends on the height the wire above the ground and diameter of the wire. Beverage Antenna has SWR close to 1.0:1.0 in a wide spectrum of the radio frequency band when the optimum value resistor is used and the antenna fed through line with impedance that is equal to the wave impedance of the antenna.

 

 Beverage Antenna has practically unidirectional radiation pattern (small back lobe of course is present) with the main lobe directed to the resistor-terminated end. The wide of the lobe depends on to ratio “used frequency: antenna length.” I believe that the paragraph gave enough theoretical knowledge to build a Beverage Antenna.

Figure 2 shows Beverage Antenna that I have installed at my backyard. Length of my Beverage antenna was equal to 20- meters. The length was fixed by the length of the fence. Antenna wire was stapled to the fence. I used to a 16- AWG (1.3- mm) wire in strong black plastic insulation. The wire was bought at sale at Home Depot- 22 cent/meter. The wire used to in electrical job. The antenna wire was placed at height 1.8- meter above the ground. Height of the fence defines it. Theoretical value of the wave impedance of my antenna was close to 500- Ohm. It is allowed me use 450- Ohm terminated resistor and transformer 1:9 to feed the antenna through coaxial cable RG8X 50- Ohm. At my case the cable had length in 50 feet. At both end sides the Beverage Antenna had RF and electrical grounding.

 

Below we discuss all parts of the Beverage Antenna.

 

 

 

 

Figure 2 Practical Design of my Beverage Antenna

 

 

Terminated resistor of the Beverage Antenna

 

I need termination resistor for my Beverage Antenna. It should be 450- Ohm, non-inductive, 20… 50- Wtts Broadband termination resistor. Power of the resistor depends on output power of used transmitter. The resistor may dissipate up to 50% of the RF power going to the antenna. It is not a problem to buy such resistor online through internet. However, the chipper one costs $ 50.0 USD. I decided make the termination resistor by myself. I bought a kit with 25 e.a. usual 4.7-kOm/2.5-Wtt metal resistors for $ 5.0 on e-bay.  Eleven such resistors switched to bridge have resistance 440- Ohm. Figure 3 shows the home- brew termination resistor. Coin in 25- cents is placed beside the termination resistor. Dissipative power of the resistor should be 27.5- Wtts. However my experiments show that the resistor could stand at least 50- Wtts for a short time.

So, the Beverage antenna may work with transmitter with output power 100- Wtts with CW and SSB mode.

 

 

 

Figure 2 Practical Design of Home- Brew Termination Resistor

 

 

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Last Updated:

May 1, 2016 22:10

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