EWE antenna
Simulated performances
160m
- Gain ~ -21dBi - Elevation angle ~ 30° Radials 2 4 8 16 32 R_optimum 833 774 680 593 523 F/B max (dB) 43 40 46 35 23 F/B with 680 Ohms 20 23 46 24 18 |
80m
- Gain ~ -11dBi - Elevation angle ~ 21° Radials 2 4 8 16 32 R_optimum 759 721 678 629 586 F/B max (dB) 18 18 24 32 32 F/B with 680 Ohms 15 18 24 27 23 |
1- Basically, when installing the EWE, you do not know how good your local ground is !
2- Time passing, your local ground effectiveness can change (dry / humid, etc....)
3- Results here above show that a # 680 Ohms resistor is a good trade-off, whatever the bands or the ground conditions are.
4- To get optimum results whatever the conditions are, a remotely variable resistor (500 ~ 900 Ohms) is a must.
2- Time passing, your local ground effectiveness can change (dry / humid, etc....)
3- Results here above show that a # 680 Ohms resistor is a good trade-off, whatever the bands or the ground conditions are.
4- To get optimum results whatever the conditions are, a remotely variable resistor (500 ~ 900 Ohms) is a must.
Optimum size for 80m operation only
Radials 2 4 8 16 32
R_optimum 811 741 640 552 488 F/B max (dB) 31 31 53 33 25 F/B with 680 Ohms 21 26 32 20 16 |
Optimum size for 80m operation
Height = 10 feet (3m) / Length = 23 feet (7m) Gain ~-18dBi Elevation angle ~27° |
1- This "smaller size" provides better F/B results for any ground conditions
2- Gain is smaller, but still above -20dBi.
3- a 680 Ohms could be here again a good trade-off for any ground conditions
2- Gain is smaller, but still above -20dBi.
3- a 680 Ohms could be here again a good trade-off for any ground conditions
4-directions coverage
To cover the 4 main directions, we can use a central pole with 4 different EWE's.
See on the right the 4-direction EWE configuration, with at the same scale, a full size K9AY.... Not everybody has the place for a 80 feet (~26m) free circle in a small city lot, but at least fitting a full size EWE along the property border should be possible to favor one direction. |
On the air performances
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