simulated using 4NEC2
(dB)*
50 / 70 MHz dual band antenna comparison
The figures given are the result of computer simulations, not real world figures !
| Antenna simulated using 4NEC2 |
Feed type | Boom length (m) | 50.2 | MHz | 70.2 MHz | NEC2 | |||||||
| Gain (dBi) | F/B (dB) | Feed Z (Ω) | DL6WU (dB)* | Gain (dBi) | F/B (dB) | Feed Z (Ω) | DL6WU (dB)* | SWR 1:2 (kHz) |
ΣDL6WU (dB)* |
.nec | |||
| DK7ZB trio 2/2 | Open sleeve | 1.1 | 6.6 | 8.8 | 50 | 0.7 | 6.4 | 11.0 | 50 | -0.6 | 1700 | +0.2 |
|
| OK1CDJ duo 2/2 | Open sleeve | 1.4 | 6.4 | 20.8 | 50 | -0.1 | 6.9 | 14.7 | 50 | -0.8 | 2700 | -0.9 |
|
| Parallel | 2.0 | 7.1+ | 17.3+ | 50+ | -0.6 | 8.2 | 17.9 | 50 | -0.6 | 3700 | -1.3 |
|
|
| G0KSC duo 4/4 | Open sleeve | 2.1 | 8.6 | 20.3 | 50 | +0.7 | 8.4 | 17.6 | 50 | -0.6 | 900 | +0.1 |
|
| GW3YDX duo 3/4 | Open sleeve | 2.2 | 7.2** | 18.7** | 50 | -0.9 | 8.9** | 21.4** | 50 | -0.3 | -1.1 | ||
| G0KSC duo 3/3 | 3.2 | 8.1 | 12.0 | 50 | -1.2 | 8.3 | 12.7 | 50 | -2.1 | 1500 | -3.3 |
|
|
| DK7ZB 5ele | Dipole | 3.2 | - | - | - | - | 10.7 | 25.9 | 28 | +0.2 | 3100 | - |
|
| G0KSC duo 4/5 | Open sleeve | 3.5 | 9.1 | 14.5 | 50 | -0.5 | 10.3 | 19.6 | 50 | -0.5 | 1100 | -0.9 |
|
| OH1ZAA duo 4/5 | Dual | 4.0 | 10.7 | 17.6++ | 16+j5.6 | +0.7 | 10.4 | 16.5++ | 6.8+j6.5 | -0.8 | 370 | -0.1 |
|
| GW3YDX duo 4/5 | Parallel | 4.1 | 9.4 | 17.0 | 50 | -0.7 | 10.8 | 13.7 | 50 | -0.5 | 750 | -1.2 |
|
| YU7EF duo 5/5 | Open sleeve | 4.2 | 10.2 | 30,3 | 50 | +0.0 | 9.8 | 18.2 | 50 | -1.5 | 2200 | -1.5 |
|
| GW3YDX duo 5/5 | Open sleeve | 4.2 | 10.1** | 29.1** | 50 | -0.1 | 10.0** | 17.6** | 50 | -1.4 | -1.5 | ||
| G0KSC duo 6/5 | Open sleeve | 4.9 | 11.1 | 17.2 | 50 | +0.3 | 10.5 | 14,9 | 50 | -1.4 | 900 | -1.1 |
|
| Dipole | 5.1 | - | - | - | - | 12.4 | 19.2 | 28 | +0.4 | 2300 | - |
|
|
| PA5DD duo 5/6 | Open sleeve | 5.4 | 10.5 | 23.4 | 50 | -0.6 | 12.0 | 20.1 | 50 | -0.2 | 700 | -0.8 |
|
| PA0TBR duo 6/6 | Open sleeve | 5.5 | 11.2 | 13.7 | 50 | +0.1 | 12.3 | 11.8 | 50 | +0.0 | 820 | +0.1 |
|
| YU7EF duo 6/7 | Open sleeve | 5.9 | 11.6 | 20.5 | 50 | +0.2 | 10.8 | 19.4 | 50 | -1.7 | 900 | -1.5 |
|
| DK7ZB 7ele | Dipole | 6.4 | - | - | - | - | 13.0 | 30.1 | 28 | +0.2 | 3000 | - |
|
| IW0FFK duo 6/7 | Dual | 7.3 | 12.3 | 9.8 | 15 - j 47 | +0.2 | 12.0 | 16.1 | 28 | -1.3 | 4000 | -1.1 |
|
| YU7EF duo 7/8*** | Open sleeve | 9.0 | 13.0 | 22.1 | 50 | +0.2 | 12.9 | 28.6 | 50 | -1.0 | 1600 | -0.8 |
|
| DK7ZB 9ele | Dipole | 10.0 | - | - | - | - | 14.6 | 34.2 | 28 | +0.3 | 2300 | - |
|
* Gain relative to regression of DL6WU
yagis for a given boom length. Formula from DJ9BV DUBUS 03/1988
[7.773*LOG(Boom/λ)+11.43]dBi
** Manufacteurs (reliable) claim
*** Published in DUBUS 02/2007, p. 77
+ Antenna optimized
for 52 MHz
++ F/B much better a bit lower in frequency. Probably because the antenna was
designed using MININEC
DK7ZB designs listed as benchmarks
The simulations are "best effort". All files have passed a segmentation check and the "Average Gain Test".
|
Note on NEC2 modelling: Dual band antennas will often give segmentation check errors because two elements of different length are close to each other. This will lead to non-aligned segments in the two elements. The trick to avoid this is to chop up the longest element into 3 wires (GW). A central wire being the same length as the shorter element, and two wires at each end to bring the element back to the original length
|
IW0FFK band isolation (simulated in MMANA-GAL by placing a load in non-excited feed element and reading magnitude of current)
| U excited feed (V) |
I excited feed (mA) |
P excited feed (mW) |
Z non-excited feed (Ω) | │I│ non-excited feed (mA) | P non-excited feed (mW) | 4m > 6m (dB) |
6m > 4m (dB) |
| 1 +j0 | 5.02+j18.16 | 18.84 | 10 | 0.981 | 0.0096 | -33 | |
| 18.84 | 50 | 0.950 | 0.0451 | -26 | |||
| 18.84 | 100 | 0.881 | 0.0776 | -24 | |||
| 1 +j0 | 35.71+j0 | 35.48 | 10 | 7.41 | 0.549 | -18 | |
| 35.48 | 50 | 6.91 | 2.387 | -12 | |||
| 35.48 | 100 | 6.07 | 3.685 | -10 |
