SteppIR Vertical Antenna
SteppIR manufactures freely tuneable multiband beams with 2, 3 or 4 elements for 40 to 6m or 20 to 6m. With the continous mechanical tuning of the element lengths SteppIR Yagis achieve the performance of comparable monoband beams - but on many bands. The similar contructed verticals offer always perfect match as tuned groundplane.
Please see here for the webpage of 'large' motor-tuned SteppIR antennas.
CrankIR Vertical Antenna
The CrankIR is a vertical antenna for portable operations, either at home, in the field or vacation. It works just like the 'big' SteppIR antennas with an antenna radiator which can be mechanically changed in length. Just that in this case the tuning does not happen by a motor drive, but by hand. Hence the name, CrankIR... The result is an always perfectly matched vertical antenna, which can be tuned to work as a Lambda/4, Lambda/2 or 5/8 Λ antenna, depending on band and radial setup.
Like the well known beams and big verticals by SteppIR, the CrankIR uses a radiator which is variable in length. To save space (height) the radiator is folded once. This greatly reduces the height of the mast and makes the antenna much more managebale for portable use in a vacation or even for backpacking. The standard mast is 4.9m high when installed. A flexible arm at the upper end holds the loop at a width of approx. 1.14m. The loop consists of a 17m long, highly flexible copper wire and a an equally long, non-conduction pull rope.
A box with the electrical connections and the crank mechanism connects two masts: the lower mast is the vertical part of a tripod or any other fixed tube (not included). On the upper side the supplied telescopic glass-fibre mast is installed. During the installation the pull rope is fed over the flexible arm on top and down again to the crank mechanism. Here two reels are mouted on the same axis, one reel winds the incoming rope, the other reel unwinds the wire. Due to the flexible, elastic arm on top the loop is always kept at tension. By cranking the reels the antenna wire is lengthened or shortened. Inside the crank box copper-beryllium contacts sit on the wire. A 1:1 current balun matches the antenna to a coaxial cable connector (PL). For operation a coaxial cable is required (not included).
Another special feature of the CrankIR is a SWR measureing device built into the crank box. When a button on the side is pressed and held down, not the balun but a resistive SWR bridge is attached to the antenna. Now you can transmit with low power (1 to 15 W max.), a LED lights up on high SWR. By careful tuning of the antenna and the radial a minimum SWR can be adjusted, the LED goes off. The is a great help in finding the exact resoance without changing cables from the transceiver to an antenna analyser.
The CrankIR vertical is quite efficient due to the design without lossy traps and without extension coils. The folded design introduces a slight loss of approx. 0.5 dB, but the benefit of the smaller antenna is too important to give up. The performance of the antenna is greatly influenced by the type and number of radials. In the base pack of the antenna (WiMO ref. 12125) no radials are included. The customer has the option of constructing a radial by herself, for example with some random wire cut to Λ/4 length on the desired band. The manufacturer suggests the use of elevated radials, i.e. radials which do not touch the ground and which must be cut to a resonant length. Optionally the radial kit ref. 12128 can be used. Wire radials are attached to a massive clamp on the bottom side of the crank unit. If only a single radial can be used it should be laid out in the main operating direction. Alternatively several radials can be laid out in different directions.
The optional 80 to 2m radial kit 12128 uses - like the radiator itself - two reels which take the copper wire and a tow rope. This reel unit is attached to the bottom side of the crank unit where it connects to the balun circuit. This allows the user to conveniently adjust the length of the radial from the same position as the radiator itself. For operations on 80m SteppIR offers a mast extension which helps the efficiency not only on 80m, but also on 40 and 30m. The 80m kit, WiMo ref. 12126, contains this mast extension as well as the 80-2m radialkit (also sold separately as ref. 12128).
The quick release clamps for the telescopic glass fibre mast are included in the shipment. In the manual, the manufacturer suggests to use electrical insulation tape to fix the segments of the telescopic mast. But in the long term these quick release clamps are a better solution. The CrankIR antenna is weatherproof and can be used outdoors in humid conditons (rain, dew etc). If any parts are immersed with salt water they should be cleaned after use to avoid corrosion. The usable 2:1 bandwidths of the antena which can be used without retuning are 120 kHz on 80m, 900 kHz on 10m and full band on all other bands.
- Included in shipment 12125 CrankIR
- Crank Box with radiator wire and rope
- 490cm glass fibre mast
- Quick Release Clamps
- Tensiner and aluminium extension
- Carrying bag
- Printed instruction manual (english)
|Frequency||6.8 to 150 MHz (with 80m extension: 3.4 to 150 MHz)|
|Max. Power||1500 W PEP|
|Radiator||Flexible copper braid, 0.8mm²|
|Balun||1:1 current balun (choke)|
|SWR bridge||Resistive, 1 - max. 15W|
|Height of mast (extended, without support tube, without 80m extension)||ca. 4,89 m|
|Height of mast (extended, without support tube, with 80m extension)||ca. 6,53 m|
|Width of cantilever arms (installed)||top: 114cm, bottom 57cm|
|Weight (12125 Antenna incl. bag)||ca. 3 kg|
|Temperature range||-45 to +50 °C|
|12125||SteppIR CrankIR Vertical antenna 40-2m||735.00 €||Buy now||In stock, shipped in 1 or two days. ▶|
|12126||SteppIR CrankIR 80m Kit||275.00 €||Buy now||In stock, shipped in 1 or two days. ▶|
|12127||SteppIR CrankIR Quick Release Clamps||22.00 €||Unfortunately this product is not available anymore. Sorry. ▶|
|12128||SteppIR CrankIR Radial kit 80-2m||184.00 €||Buy now||Not in stock, ordered only on customer request, delay at c. 50 days. ▶|
|Info freight charges|