Last question before I will start building. Can I lift antenna 2m over the ground and use elevated radials? How this will affect antenna performace and radiating angle? Or maybe it will be better to leave it as it is on the ground level. Mike
So If I want only 80/40 tophat and top coil is not needed and antenna will be a little shorter? Can you calculate dimensions for SSB part? Mailny I will use that antenna between 3750 and 3800. On 40m between 7 and 7.2MHz mainly around 7.1MHz. Thank you, Mike
>A 20.5 m vertical (35 mm diameter used in simulation) is directly driven against ground. This is resonant at 3.5 MHz. I can do it. You mean ground rod or radials?
>A 10.5 m grounded wire is spaced 40 cm from the vertical. It is parasitically excited and is resonant at 7 MHz. The spacing from the vertical determines the 7 MHz input impedance. You mean paralel to the antenna? Where will be the feed point?
>The ground consists of sixteen 10 meter radials. I already have more of them.
>A 31 uH series inductor at the base resonates the antenna at 1.8 MHz. I can use remote controlled variable inductance coil and tune that with VNA.
>To improve this the vertical can be top loaded using a top hat and a top inductor. The base inductor can be used to fine tune it. Perhaps 5 uH at the base. If this sounds good I will model a top hat for you.
Hi. The goal is to have best possible performing vertical antenna for 80/40m. If it will work on 160m would be great. I already have 40m vertical with radials on the ground. I have k9ay for RX.
What I can do: 1. I can put around 20m high vertical in those place. 2. I can use variable inductance coil at the bottom of the vertical (0-80uH) 3. I can put a few 20m long radials on the ground. I can lift antenna 2m above the ground and use resonant radials if it will do the trick.
Limitations are: I don't have high supporting trees or tower to hang wires from that. Garden is not so large, so I can have as many 10m long radials as I want, but longer ones only a few.
Is there any way to have good performing, low angle radiating antenna for those bands? Thanks, Mike
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