InnovAntennas Delta-C140 Rotary Dipole 40m
Available in 25 days
- SWR =< 2:1 (<1.6:1 up to 7.2 MHz)
- Only 12m long
- 89% efficiency
- Delta-C140 Antenna
- Pole clamp 50mm
Technical description Delta-C140
The Delta-C140 from Innov Antennas is a rotary dipole for the 40m band
with particularly good efficiency. The element length (width) is only
There are several methods to shorten a dipole, including extension coils and roof capacitors at the element end. With coils, position is critical to efficiency - further in the middle at the feed point is mechanically easier, further out is electrically better. Justin, G0KSC has used both methods to build the Delta-C140 antenna robustly and efficiently, limiting the size to a dimension that many radio amateurs can still install on the mast. The Delta-C140 has coils in the centre of the radiator halves and roof capacitors at the ends.
The Delta-C140 dipole does not need any guy wires! The fact that individual pictures show this antenna with guy wires is the individual decision of the operator, for example because a lot of snow is expected in winter. The construction is designed for heavy loads, so the element has a large diameter of 55mm with 2mm wall thickness in the middle. The thickness decreases rapidly towards the outside to save weight, but the ends still have a diameter of 25mm.
The coax connection is uncomplicated via screw terminals, without balun. For insulation of the cable we recommend 'Rubbaseal', a liquid rubber coating for cables. The maximum permissible transmitting power is 3000 W.
Application description Delta-C140
The 40 m band is particularly attractive due to its propagation
conditions, also and especially for contest participants. Depending on
the time of day, both local and international connections are possible.
However, due to the relatively long wavelength, a good antenna for 40m
is a challenge, because not everyone has the space to hang a full-length
dipole. Here InnovAntennas offers a very good solution with the
Delta-C140 Rotary Dipole.
Even if the Delta-C140 dipole cannot be rotated (what wire dipole can be rotated?), this antenna offers an excellent solution for operation on 40m with relatively small space requirements. The shortening of the dipole halves is done both by extension coils and roof capacitors at the ends of the radiator. The advantage of this design is a very large usable bandwidth of the antenna - the Delta-C140 can be used over the entire internationally approved range from 7.0 to 7.3 MHz without having to use a tuner. The SWR is usually less than 2:1. In the range from 7.0 to 7.2 MHz, the SWR is usually equal to or better than 1.6:1. The efficiency of the antenna is 89%!
All in all, the Delta-C140 antenna combines a carefully calculated design with a very robust construction. This is also supported by the materials used: UV-resistant insulators, seawater-proof stainless steel elements and aluminium from aircraft construction. The result is a rotary dipole with high efficiency, which, with a width of only 12m and a weight of only 8.5 kg, will cause enthusiasm among many radio amateurs.
|Max. Element Length||12|
|Impedance (Ω)||50 Ohm|
|Bandwidth (kHz)||300 kHz (2:1), 200 kHz (1.6:1)|
|Number of connectors||1|
|Max. Power [W]||3000 W|
|Frequency Range||7 - 7.3 MHz|
|Rotation Radius [m]||6.92|
|Design of antenna||Rotary Dipole|
|Antenna mount||Center Mount|
|Max. Mast Diameter [mm]||50|
|Max. Windspeed (km/h)||172 km/h|
|Gain [dBi] (free space)||2.1|
|Gain 7 MHz [dBi]||2.1|