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No reflector. No director. No radials. Less than a quarter-wave turning radius. Close to the 6dBi of a Moxon plus bi-directional! How can this be? I too was surprised when I stumbled onto it. Let me tell you how.
Recently I have been using and optimizing a variant of the off-center-fed (OCF) L-dipole initially described in e-Ham article #31424. To compare performance to my conventional 10M dipole I bought an antenna switch at the recent Hamcation Orlando. Now when transmitting, this allows me to rapidly switch antennas so that other hams could tell me which antenna is stronger. Also by switching when listening, I sorted out the L-dipole directional characteristics and curiously, noted polarization meandering on multi-skip/path signals. Overall the results were quite satisfying but raised the question: What are the effects of changing the angle of the lower arm of a bent vertical dipole?
To find out the effects, I turned to wire antenna simulation by using the modeling program 4NEC2. This allowed the setting of dipole height over ground, length of dipoles and bend angle of the lower dipole arm. Here are the results graphically.

Following is a verbal summary of the associated 4NEC2 polar plots and color 3-D images.
Basic Vertical dipole. 10 meters, 12 feet high, #12 AWG wire
Lower arm raised 30 Degrees away from vertical
Lower arm raised 60 Degrees
(Note: 50 ohm impedance and balance between vertical and horizontal polarization occurs with lower arm at 75 degrees).
Lower arm at 90 Degrees
Lower arm at 120 Degrees up from vertical
Generally,
Currently I use the L-Dipole set to about 100 degrees for DX East to West. My horizontal half-wave dipole is for North to South. If I get excited about getting into a pile-up, I will go out and aim the L-Dipole. And yes, I have thoughts about a rotator and remote angle adjustment as well as having dabbled with vertical tilt to aim the angle of radiation lower.
73 de KK4OBI
| WB4DX | 2022-04-13 | |
|---|---|---|
| Re: 10-Meter Dipole with 5 Db Gain | ||
| Good one! Reply to a comment by : ZL1RD on 2021-09-03 Another "expert" that has no idea what an antenna is or how it works. Dipoles do not have 5db gain... period. | ||
| ZL1RD | 2021-09-03 | |
|---|---|---|
| 10-Meter Dipole with 5 Db Gain | ||
| Another "expert" that has no idea what an antenna is or how it works. Dipoles do not have 5db gain... period. | ||
| KT4WO | 2021-08-21 | |
|---|---|---|
| Re: 10-Meter Dipole with 5 Db Gain | ||
| I want one of those 6dbi Moxons!!! lol Reply to a comment by : W4OP on 2021-08-21 Wait a minute. You are comparing your antenna above real ground with a Moxon in free space.Did you model a Moxon above real ground at the same height as your L? I think you will be very surpised that the gain you ascribe to the Moxon is about 6dB below a Moxon above real ground. Dale W4OP | ||
| W4OP | 2021-08-21 | |
|---|---|---|
| 10-Meter Dipole with 5 Db Gain | ||
| Wait a minute. You are comparing your antenna above real ground with a Moxon in free space.Did you model a Moxon above real ground at the same height as your L? I think you will be very surpised that the gain you ascribe to the Moxon is about 6dB below a Moxon above real ground. Dale W4OP | ||