In addition to the SteppIR Yagis, there are also two vertical operating with the same elegant principle. A metal band of beryllium copper extends or retracts inside a vertical tube made of fiberglass. The band is processed with a stepper motor, changing the electrical length of the antenna without lossy traps, load coils. etc..
This type of antenna, of course, requires a good radial network (not included). The radial network significantly influence the efficiency and irradiation angle of the antenna. Especially for the verticals that are famous for its low radiation angle favoring the DX.
The radial network can be designed as either radial ground elevation as either radial. The λ/4 lengths require elevated radials, at least two per band. The ground radials can be of any length but at least long λ/10 or more, even better. The operator's Manual of SteppIR vertical advises many other helpful tips to build a good network of radial.
There are two types of vertical antennas: SmallIR cover from 20 through 6 meters, BigIR covers from 6 m to 40 (with option for 80 m). PE i technical data see table below.
|SmallIR Mk3 Vertical||BigIR Mk4 Vertical|
|Frequency range (continous)||13.8-54||6.9-54||MHz|
|Max Wind speed||~ 160||~ 130||km/h|
|Required control cable||4||4|
8 mit 80 m Spule
Prices, images and descriptions are approximate. Specifications are subject to change during construction of the supplier.