Bob and I have been discussing gamma losses on another thread on various radiator lengths for the New Vector 4K. I can't prove a gamma is more lossy or less efficient than direct feed or another kind of matching.
However, this project below was my 1st effort to see for myself if different setups for a Horizontal CF dipole produced dramatic difference in gain, match, resonance, and Common Mode Currents that are likely due to similar lossey situations. We've all heard stories about these issues over time on this forum, other forums, and on the air.
Note #1 - The models below show the base line model and various configurations used to demonstrate what losses might do for a model.
Examples of such situations:
1. What does an HCF dipole look like...showing the basic matching results that antenna science reports for this design?
2. What is likely to happen to a model if we add a mast that is not isolated, connected directly to the antenna?
3. What is likely to happen if we add a simple coaxial choke where the mast and the antenna are connected directly together without isolation (ISO)?
4. What is likely to happen if we ISO the antenna at the top of the mast and don't add a choke?
5. What is likely to happen if we take antenna #2 antenna above that is not ISO and add a feed line that is the actual distance to the Earth? 36' feet in this case?
6. What is likely to happen if we add a coaxial choke to the top of the mast on model #2 and include the feed line to the model?
Each model shown is made up of the following images:
a. image of the antenna view along with the dimensions of wire #1 of the 2 wire antenna radiator. You will also see other wires included or added to change situations as noted for this idea.
b. image of the pattern showing the gain and angle with other performance details noted.
*********Also see Note #2 below.
c. image for the SWR bandwidth scan report, showing the <2.00:1 SWR bandwidth curve and the center frequency at the resonance point along with other performance details.
d. image is the Source Data Report showing the feed point condition for values of Impedance, Reactance, SWR, and the power the model made at 1(Amp) of current.
*********Note #2 - in some of the pattern images you will sometimes see a red line for the currents noted for the vertical polarization pattern on this horizontal dipole. This means the mast is radiating RF to some degree depending on the magnitude for currents. Keep your eye on these red lines in the pattern view...you should also see such a red line for CM currents on the mast in the antenna view.
However, this project below was my 1st effort to see for myself if different setups for a Horizontal CF dipole produced dramatic difference in gain, match, resonance, and Common Mode Currents that are likely due to similar lossey situations. We've all heard stories about these issues over time on this forum, other forums, and on the air.
Note #1 - The models below show the base line model and various configurations used to demonstrate what losses might do for a model.
Examples of such situations:
1. What does an HCF dipole look like...showing the basic matching results that antenna science reports for this design?
2. What is likely to happen to a model if we add a mast that is not isolated, connected directly to the antenna?
3. What is likely to happen if we add a simple coaxial choke where the mast and the antenna are connected directly together without isolation (ISO)?
4. What is likely to happen if we ISO the antenna at the top of the mast and don't add a choke?
5. What is likely to happen if we take antenna #2 antenna above that is not ISO and add a feed line that is the actual distance to the Earth? 36' feet in this case?
6. What is likely to happen if we add a coaxial choke to the top of the mast on model #2 and include the feed line to the model?
Each model shown is made up of the following images:
a. image of the antenna view along with the dimensions of wire #1 of the 2 wire antenna radiator. You will also see other wires included or added to change situations as noted for this idea.
b. image of the pattern showing the gain and angle with other performance details noted.
*********Also see Note #2 below.
c. image for the SWR bandwidth scan report, showing the <2.00:1 SWR bandwidth curve and the center frequency at the resonance point along with other performance details.
d. image is the Source Data Report showing the feed point condition for values of Impedance, Reactance, SWR, and the power the model made at 1(Amp) of current.
*********Note #2 - in some of the pattern images you will sometimes see a red line for the currents noted for the vertical polarization pattern on this horizontal dipole. This means the mast is radiating RF to some degree depending on the magnitude for currents. Keep your eye on these red lines in the pattern view...you should also see such a red line for CM currents on the mast in the antenna view.
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