SteppIR Antennas


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 similiar contructed λ/4 verticals offer always perfect match as tuned groundplane. The small packing size and the lightweight construction with glassfibre tubes makes these antennas an ideal companion for dx-peditions and fielddays.

The problem with traditional beams

Traditional multiband beams require traps, interlaced elements etc. to work on multiple bands. With these elements such an antenna is usually a compromise in respect to the possible maximum efficiency of an antenna. Monoband beams like the ZX Yagis would be an alternative, but who can put up three or more such beams?

The idea: variable lengths elements

Bild SteppIR 2-elementFluidMotion, the manufacturer of SteppIR antennas has solved this problem in an elegant way. SteppIR vary the mechanical length of each element by means of a retractable metal band. This allows the antenna to be adjusted for any frequency (within the range) and work near the perfect optimum.


Contruction of a SteppIR

Each element of a SteppIR antenna consists of lightweight glassfibre tubes, the metallicc band run in these tubes. That means of course that the absolute size of the antennas does not change, the glasfibre tubes are not changed in length. The metallic bands are made of a special Copper Beryllium (CuBe) which withstands millions of movements. The excellent electrical contact is achieved with four self cleaning slider contacts for each element. The metal band itself is perforated, a sprocket wheel spools up the band. The sprocket is driven by a precision stepper motor, allowing for very precise positioning.


Each single element is controlled by a 4 wire cable, i.e. the 4-element SteppIR yagi requires 16 wires. Down in the shack a supplied controller is used to adjust the antenna. For the amateur bands various presets are available for each band. Further a "general" mode allows adjustment of the antenna to any frequency (within the specified range). Antenna setups can be stored for later recall, other functions allow the quick reversal of direction or the bi-directional mode where the gain is evenly distributed in two directions. An optional CAT interface for the controller allows direct control from most amateur rigs: the antenna is continously adjusted when the frequency on the rig is changed.

Optional 30/40m Radiator

This replaces the standard radiator and allows operation down to 40m. Available in two version: one as option when buying a new antenna and one as replacement part for an existing antenna.

Technical data and comparison table
  Dipol 2 Element Yagi 3 Element Yagi 4 Element Yagi DB-11 DB-18 DB-18E DB-36 DB-36
with 80m
DB-42 DB-42
with 80m
Frequency range (continous) 13,8 - 54 13,8 - 54 13,8 - 54 13,8 - 54 13,8 - 54 6,8 - 54 6,8 - 54 6,8 - 54 3,5 - 54 6,8 - 54 3,5 - 54 MHz
Max. Power 3 3 3 3 3 3 3 3 3 3 3 kW
Weight 4,5 13,6 19,0 34 28.6 41.2 45.3 72.8 74.4 108 109 kg
Antenna surface 0,17 0,37 0,57 0,90 0.54 0.9 1.1 1.63 1.63 1.85 1.85 m2
Max. Wind speed ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 ~ 160 km/h
Longest Element 10,97 10,97 10,97 10,97 5,79 11,88 11,88 14,9 14,9 14,9 14,9 m
Rotating radius 5,48 5,53 6,00 7,35 3,20 6,50 6,50 8 8 8,8 8,8 m
Boom length - 1,44 4,87 9,75 3,35 5,80 5,80 10,97 10,97 10,97 10,97 m
Boom diameter - 4,5 4,5 4,5 & 5,7 4,45 5 5 4,5-6,35 4,5-6,35 13 13 cm
Max. Mast diameter 53 53 53 53 53 53 53 53 53 53 53 mm
Required Control cable 4 8 12 16 16 16 16 16 24 25 25 Wires
Balun incl. No (optional) Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes  
Order No. 12100.1 12100.2 12100.3 12100.4 12113 12115 12115.E 12116 12116.80 12117 12117.80  
Price 1392.00  1839.00  2471.00  3564.00  3197.00  3769.00  4399.00  6187.00  6100.00  7200.00  7900.00  Euro
Order No 6m Option     12100.63 12100.64   12100.63 12100.63          
Price     107.00  107.00  107.00  107.00        Euro
Order No. incl. 30/40m Dipole   12105.2 12105.3 12105.4                
Price   2432.00  3046.00  4072.00              Euro

1 According to the manufacturer operation on 30m may require a tuner.

SteppIR Dipoles and Yagis

Bild SteppIR §-ElementThe SteppIR Dipole and Yagis are available in five different versions, from one to 4 elements, covering different ranges. Each element is variable in length by using a motor driven metal band (Copper Beryllium). The metal band is protected by a glasfibre tube, the length of this tube does not change of course.

Like with all SteppIR antennas the glassfibre tubes have to assembled and isolated at first set up. This makes the SteppIR antennas very compact, that nice for shipment cost and expeditions.

Variable element length, but fixed element distance?

One of the most frequently asked questions is "Shouldn't the distance of the elements also change when changing element lengths?". To answer this question it is important to understand that Yagis can be designed to maximise different values. That can be max. gain, best Front/Back ratio, good bandwidth etc. But - these goals cannot be achieved all at once with the same design. Either you optimize a yagi for best gain, useful bandwidth and not so good F/B ratio. Or excellent F/B ratio at narrow bandwidth and mediocre gain etc. etc.

With a 3-element beam the optimum gain would be reached at a boom length of 0.4 λ. The best F/B ratio is achieved with a boom length of approx. 0.25 λ, but only at limited bandwidth. This results in 0.3 λ as a good compromise, with this it can be shown that a variable element length results in much greater effect than variable distance. Bandwidth is of no importance with a SteppIR antenna because the antenna can be adjusted to any operating frequency (within specified range). So a narrow bandwidth design can be selected which results in the best compromise solution at a given element distance. That is much more than what you can expect from a traditional monobander.

Gain and Front/Back ratio
  Dipol 2 Elem. Yagi 3 Elem. Yagi 4 Elem. Yagi 4 Elem. Yagi MonstIR DB-11 DB-18 DB-18E DB-36 DB-42
40m - - - - - - - - 7,8 25 - - 6,2 20 6,2 20 7,2 221 8,8 25,5
30m - - - - - - - - 8,2 20 - - 5,4 - 7,0 20 8,2 18 9 12,4
20m 2,1 0 4,2 18 5 42 9,5 21 9,5 21 6,4 19,5 7,4 25 7,4 25 9,3 22 10,1 22
17m 2,1 0 4,2 19 5,5 44 10 20 10 20 6,1 16,2 8,3 25 8,3 25 9,9 27 10,8 22
15m 2,1 0 4,1 14 5,7 44 10,2 27 10,2 27 7,1 21,4 8,5 20 8,5 20 10,2 27 11 25,7
12m 2,1 0 4,0 13 6,2 17 10,4 21 10,4 21 7,3 23,2 8,8 15 8,8 15 10,4 21 11,9 24,1
10m 2,1 0 3,8 10 6,3 15 10,6 11 10,6 11 7,5 24,55 9,0 11 9,0 11 10,7 11 12,2 20
6m 2,1 0 2,6 1,5 3,0 4 7 7 7 10 8,7 15,1 6,2 4 6,2 4 4 2 4 2
Order No.
12100.1 SteppIR Dipole 20-6m with controller 1392.00
12100.2 SteppIR 2-Element 20-6m Yagi with controller 1839.00
12100.3 SteppIR 3-Element 20-6m Yagi with controller 2471.00
12100.63 6m Option for 3-elem. Yagi 107.00
12100.4 SteppIR 4-Element 20-6m Yagi with controller 3564.00
12100.64 6m Option for 4-elem. Yagi 107.00
12105.2 SteppIR 2-elem. with 30/40m Radiator 2432.00
12105.3 SteppIR 3-elem. with 30/40m Radiator 3046.00
12105.4 SteppIR 4-elem. with 30/40m Radiator 4072.00
12142 CAT interface for controller 111.00
12146 Y-cable for CAT 53.00
12155.RUBBER Spare part Rubber sleeve on EHU 11.30


SteppIR Dream Beam DB-11

SteppIR DB-11 Beam

The DB-11 is the smallest beam of SteppIR Yagi antenna which uses the loop technology. This allows the full performance can be achieved despite a 40% smaller area.

The DB-11 has an integrated coaxial switch that selects which is the radiator of the 3 elements in order to ensure the same performance in both directions. The control of the switch is integrated into the control unit SDA 100. The DB-11 is the only 6m antenna without optional element, because the distance of the 3 elements to each other is ideal for operating in this band.

SteppIR DB-11 Beam

With two active elements on 20m and 3 semi-active elements on 20m, the average gain is 7 dB and the front / back ratio 20dB per band.

Order No.
12113 SteppIR DB-11 3197.00


SteppIR Dream Beam DB-18, DB-18E
SteppIR DB-18 Beam
SteppIR DB-18E Beam

The DB-18 beams by SteppIR extend the well known antenna principle with variable length elements. With the previously existing SteppIR Beams the 30/40m element was the only element for these bands, resulting in no gain compared to a dipole. The Dream Beam uses 2 (DB-18) or 3 (DB-18E) such folded elements to achieve a gain and good front/back ratio also on 30 and 40m.

Both antennas, the DB-18 and the DB-18E, offer an automatic selection of the driven element, depending on frequency and 180° reversal. This is because shortened elements don't work well as directors, so the radiator is switched from the center element to one of the outer elements. The other two elements act as refelectors in this case.

The switching of the feedline is done with a solid 5KW, 3 port antenna switch. The switch and the required cables to each element are included in the shipment. The selection is done automatically by the new SDA-100 controller, which is included with these antennas. Both Dream Beam antennas require a control cablw with 16 wires (3x4 for elements, 1x4 for switch).

Order No.
12115 SteppIR DB-18 3769.00
12115.E SteppIR DB-18E 4399.00


SteppIR Dream Beam DB-36, DB-42
SteppIR DB-42 Beam

SteppIR DB-36
In the series of large antennas by SteppIR we offer two new models. The DB-36 has the dimensions of a conventional multi-bandyagi and is still always a mono-band beam. In addition to those already contained bands from 6m to 40m, this antenna can be increased with a 80m option.

SteppIR DB-42 (MonstIR PRO)
The world's largest Yagi antenna with a dynamic system. The DB42 has 5 elements on 20m-6m and 3 elements on 40/30. For those who aspire to the top of performance, the DB42 provides a frequency range from 80m to 6m (80m dipole with optional kit). The 6m option adds 3 passive elements without increasing the surface wind. Thus, the DB42 on 6m total of 8 elements with a gain of 14.0 dBi and 25 dB front / back ratio.


Order No.
12116 SteppIR DB-36 6187.00
12116.80 SteppIR DB-36 with 80m 7015.00
12117 SteppIR DB-42 8280.00
12117.80 SteppIR DB-42 with 80m 9095.00


SteppIR vertical antennas

Bild SteppIR Vertikal

Besides the SteppIR Yagis two vertical are available which work with the same elegant principle. In a vertically mounted glassfibre tube a metal band made of CuBe is extended or retracted. The band is wound with a stepper motor, changing the electrical length of the antenna, without lossy traps, loading coils etc.

This type of antenna of course requires a good radial network (not included). The radial network strongly affects the performance and critical values like radiation angle of the antenna. And especially vertical antennas are known for the low take-off angle, good for DX.

Radials networks can be designed either as elevated radials or ground radials. Elevated radials require tunes lengths at λ/4, at least two per band. Ground radials can be of any lengths, but at least λ/10 in length, the more the better. The operators manual of the SteppIR verticals gives many more useful hints for constructing a good radial network.

Two verticals are available: the SmallIR covers 20 to 6m, the BigIR covers 6m to 40m (with option up to 80m). Technical data see table below. Included with the vertical SteppIR antennas is the SDA-100 controller.

  SmallIR Mk3 Vertical BigIR Mk4 Vertical  
Frequency range (continous) 13,8 - 54 6,9 - 54 MHz
Max. Power 3 3 kW
Tuning Speed 1,17 1,17 MHz/s
Weight 5,44 6,8 kg
Antenna Surface 0,09 0,17 m2
Max. Wind speed ~ 160 ~ 130 km/h
Height 5,49 9,75 m
Required control cable 4 4
8 with 80m coil
Balun included No No  
Order No. 12120.V20 12120.V40  


SteppIR 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.

Crank box

Crank box with option 80m radial kit 12128


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 conenctor (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 15W 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).

Another option are quick release clamps (ref. 12127) for the telescopic glass fibre mast. 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 120kHz 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
  • Tensiner and aluminium extension
  • Carrying bag
  • Printed instruction manual (english)
Included in shipment 12125 CrankIR

Optional quick release clamps 12127  

Technical Data CrankIR
Frequency 6.8 to 150 MHz (with 80m extension: 3.4 to 150 MHz)
Max. transmit power 1500W 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


Order No.
12125 SteppIR CrankIR Vertical antenna 40-2m 599.00
12126 SteppIR CrankIR 80m Kit 309.00
12127 SteppIR CrankIR Quick Release Clamps 24.90
12128 SteppIR CrankIR Radial kit 80-2m 208.00


80m extension coil for BigIR Antenna

Extension coil for BigIR vertical antenna, enables operation also on the 80m band. Max power load 500W (1600W with new BigIR Mk3). Requires 4 additional wires in the control cable.

Order No.
12120.V20 SmallIR Mk3 Vertical 20-6m 1099.00
12120.V40 BigIR Mk4 Vertical 40-6m 1378.00
12120.V80 BigIR Mk4 Extension only 483.00


SteppIR Controllers


SDA-100: Controller for all SteppIR Antennas

SteppIR SDA-100 ControllerThe SDA-100 offers an improved lightning protection on the driver circuits, compared to the standard controller. The driver chips are now socketed for easier replacement.
Additionally we offer (optionally) the 'advanced lightning protection' (ALP), with add more protection against lightnings and static discharge.
The CAT control (requires CAT option) can be switched on and off with a button. A blinking LED shows if the antenna is currently tuning or not.

Further details:

Tuning Relay for SDA-100

Prevents the keying of a power amplifier while the antenna is tuning, avoiding damages to the antenna.

Order No.
12150 SDA-100 without ALP 652.00
12150.ALP SDA-100 with ALP Note: The ALP option can not be retro-fitted. 907.00
12150.TR Tuning Relay Board for SDA-100 125.00
12150.CAT CAT Option for SDA-100 131.00


CAT Interface Option

CAT Option SDA-100

An option for the controller is a serial CAT interface. With this option the controller can be connected to most radios, the antenna adjustment is following the tuning of the radio. SteppIR does offer suitable cablöes for most radios. The simultaneous use of the CAT interface for the antenna controller and a logging program requires a "Y" connector (order no. 12146).

Order No.
12142 CAT interface for standard controller 112.00
12150.CAT CAT interface for SDA-100 controller 131.00
12145.I Cable SteppIR - Icom 32.00
12145.FT1000 Cable SteppIR - Yaesu FT-1000MP 19.50
12145.FT897 Cable SteppIR - Yaesu FT-897 24.00
12145.TS480 Cable SteppIR - Kenwood TS-480 24.00
40060.FF Serial Cable 9pin f/f (suitable rigs see list) 3.00
MK-ILINK-STE Cable SteppIR - microHAM MK-2 38.50
40060.FFX Serial Cable 9pin. f/f crossover (Null modem, psuitable rigs see list) 3.60
40060.MF Serial Cable 9pin. m/f (suitable rigs see list) 3.60
12146 "Y" adaptor 53.00



SubD 25 Adaptor
Order No.
12149 SubD-25 Screw Terminal Adaptor SteppIR 40.00


33V Power supply

Replaces the supplied 24V power supply, recommended for cable lengths over 60m.

Order No.
12143 33V Power supply SteppIR 132.00


Control cables for SteppIr antennas

Each element of a SteppIr antenna requires four control wires. We offer cables with 6, 12 or 16 wires with 0.14mm² or 0.34mm² cross section. This is sufficient for cable lengths up to 20m. For larger distances the manufacturer suggests to use larger diameter wires or use of a voltage booster (optional 33V power supply).

Unfortunately we don't carry 8 wire control cables for this purpose (the 8 wire rotor control cable is too large). Best is to use our 12-wire cable and use only 8 of those wires.

Order No.
40012.6 6-wire 0,14mm² per Meter 0.80
40012.12 12-wire 0,34mm² per Meter 1.80
40012.16 16-wire 0,34mm² per Meter 2.85


Troubleshooting guide

Due to the new working principle of the SteppIR antennas it can happen that something is misunderstood or incorrectly asembled. For cases where the antenna is not working as expected, SteppIR offers this document (PDF, english, 120KB) which helps you locating the trouble. ALthough this document was written with 3-ele and 4-ele Yagis in mind it is helpful for any model of SteppIR antennas.

Troubleshooting Guide 3-ele/4-ele SteppIR Yagis. (PDF, Englisch, 120KB)

Software Upgrade Kit

SteppIR offers a Software Upgrade Kit for all antenna controllers. This upgradee is mainly adressed to customers who use the passive 6m element and who plan to use the new 30/40m dipole element. The upgrade requires the exchange of the CPU chip (see below).

Among others the following features were added or improved:

Order No.
12144.2 SteppIR Software Upgrade Kit for 2-Element beam 39.00
12144.3 SteppIR Software Upgrade Kit for 3-Element beam 39.00
12144.4 SteppIR Software Upgrade Kit for 4-Element beam 39.00


Download English description of Software 6.7 (6704) (PDF, english, 100KB)
Download English procedure for CPU exchange (PDF, english, 4,7MB)


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