Can I reduce the size of the original EWE ?
The answer is simple : YES.
EWE antenna are characterized by their height, and their length. By playing on those parameters, and by adjusting the terminating resistor for F/B, it is possible to find some acceptable performances while keeping the same cardioid pattern of the full-size version. Trade-off is to be found is using the EWE on several bands. I decided to go for a dual-band 160/80m EWE.
Results here below have been obtained
- Using MMANA-GAL
- Using a simulated 4-radial configuration;
- Optimizing termination load for maximum F/B on both 160 and 80m, and for each given size of the antenna.
Those are simulations, thus not exactly elevant from a final installation. But they give a good trend on how EWE performances vary versts size and Rterm.
EWE antenna are characterized by their height, and their length. By playing on those parameters, and by adjusting the terminating resistor for F/B, it is possible to find some acceptable performances while keeping the same cardioid pattern of the full-size version. Trade-off is to be found is using the EWE on several bands. I decided to go for a dual-band 160/80m EWE.
Results here below have been obtained
- Using MMANA-GAL
- Using a simulated 4-radial configuration;
- Optimizing termination load for maximum F/B on both 160 and 80m, and for each given size of the antenna.
Those are simulations, thus not exactly elevant from a final installation. But they give a good trend on how EWE performances vary versts size and Rterm.
EWE optimum resistor versus band, versus size
Common resistor value (Ohms)
160m Height (m)
2 3 4 5 2 452 342 284 252 Length 4 722 547 471 413 (m) 6 911 695 588 532 8 1017 807 683 610 10 1114 872 758 683 |
80m Height (m)
2 3 4 5 2 452 358 324 322 Length 4 694 565 502 478 (m) 6 839 686 616 592 8 934 760 692 658 10 981 820 734 698 |
Band results (Gain, F/B, elevation angle)
160m Height (m)
2 3 4 5
2 -40 / 23 / 24 -37 / 20 / 28 -34 / 17 / 28 -32 / 14 / 28 Length 4 -35 / 25 / 25 -32 / 22 / 25 -30 / 20 / 29 -28 / 18 / 29 (m) 6 -32 / 30 / 27 -29 / 26 / 26 -27 / 23 / 26 -25 / 21 / 29 8 -30 / 43 / 24 -27 / 32 / 27 -25 / 27 / 26 -23 / 23 / 26 10 -28 / 30 / 25 -26 / 57 / 24 -23 / 37 / 24 -22 / 28 / 28 |
80m Height (m)
2 3 4 5
2 -30 / 21 / 29 -26 / 16 / 30 -24 / 12 / 30 -21 / 10 / 30 Length 4 -25 / 29 / 28 -22 / 23 / 30 -19 / 18 / 30 -17 / 15 / 30 (m) 6 -22 / 32 / 28 -19 / 35 / 29 -17 / 25 / 30 -15 / 21 / 33 8 -20 / 20 / 30 -17 / 29 / 28 -15 / 48 / 30 -13 / 31 / 32 10 -18 / 15 / 31 -16 / 18 / 33 -14 / 24 / 31 -12 / 29 / 33 |
What do we see ?
- F/B peaks when length = 2x height on 80m and when length = 3x height on 160m
- At a given size, optimum Front to Back ratio is obtained with quite similar resistor value
- F/B peaks when length = 2x height on 80m and when length = 3x height on 160m
- At a given size, optimum Front to Back ratio is obtained with quite similar resistor value