The Arctic King is  a relatively  simple structure, but there are some aspects of the design that are not immediately obvious.

An inverted L antenna mirrors another inverted L antenna working against elevated radials, positioned right on the edge of salt water for more than 180° of the horizon.

At present the vertical wires going to each inverted L are tied together in the feed point box. This makes the antenna work as a T antenna against elevated radials.

In this mode – i.e. vertical wires working in Common Mode (CM), the antenna is fully resonant around 1838 kHz – a little bit high on purpose – ball park resonance was adjusted roughly by adjusting the length of the elevated radials and fine tuning of the resonance was done with a  coil connected to the center point of the elevated radials inside the feed point box and one terminal of the UNUN transformer.

There are no tuning devices in the box, i.e. the resonance adjustment of the antenna is entirely separate from the matching to the feeder.

At resonance the feeder matching is accomplished with an UNUN 4:1 i.e. 50:12.5 ohms, and the UNUN additionally provides the DC path for the entire structure to a buried ground system.

I mention somewhere on my web site that initial testing comparing this antenna with my old tx antenna for 160 meters showed a 15 dB increase in signals, but I have now done some more testing and in the salt water direction the difference is in the region of  30-40 dB.

The primary purpose of the Arctic King is being a vertically polarized antenna, but by separating the two vertical wires inside the feed point box, the antenna can be fed in Differential Mode (DM) as a low dipole antenna – again resonant on the frequency of choice at 160 meters.

This would create a high angle of radiation, useful for local contacts like EU.

When the time comes to accomplish this, resonance will be determined – my measurements indicate 1770 kHz in DM and the resonance will be shifted with a capacitor connected between the two vertical wires inside the feed point box.

If the resonant frequency is high in DM, a coil will be installed instead between the vertical wires to adjust resonance, and the resulting R will then be matched to the feeder.

(note that in CM, these resonance adjustment components will ´disappear´ in CM, since they are effectively shorted out )

The interesting thing that was discovered during modelling was that once the elevated radials were raised to around 4 meters above ground, the dimensions of the top loading wires became non-critical.

This fact made it possible to calculate first the dimensions for the DM (dipole),then use those dimensions for the CM (vertical T ) and then adjust the CM antenna (the vertical) for resonance by adjusting the lengths of the elevated radials without affecting the resonance of the dipole.

I installed 8 conductors + shield from the shack into the feed point box to control relays and make measurements.

Current will be measured on each vertical wire and on each elevated radial and the balance will be adjusted as necessary.

In addition, the vertical will also be made to work on 80 meters in both CM and DM.

On 80 meters the feed point will be at a very high impedances, this is the reason for the separation of wires from the wooden structure and the large insulators.

The Arctic King is a unique antenna professionally designed by Villi, TF3DX and I am certain that in due time, he will publish a paper detailing the Arctic King design.