Grazioli MV7, 7-Band Vertical Antenna

V7 by Grazioli antennas is a multiband 1/4  Ground Plane vertical that operates in the following HAM bands: 40, 20, 17, 15, 12, 10, and 6m. It is built on the basis of the now well-established MV6, from which it takes almost all the mechanics, with the exception of the central whip which is now Dual-Band (40+20m), obtained by adding a coil with a capacitive hat, which decouples the lower part of the 20m, and at the same time creates an adequate inductive charge for the 40m band. The remaining radiating part above the coil, about 2.2m high, is composed of two telescopic tubes sized to offer minimum wind resistance, and is adjustable for perfect tuning within the entire 40m band, the total height of the central radiator is about 8.4m, and the overall weight is 8.5Kq, (only 750g more than the MV6). The MV7 uses a modified “Ground Plane” compared to the MV6, with an innovative system called: DBFC acronym for “Dual Band Folded Counterpoise” which makes this system unique in its kind (Patent pending). The DBFC system creates a Dual-Band electric counterweight, where a 19-strand AISI316 stainless steel rope with a diameter of 1mm, highly flexible and lightweight, is anchored at the tip of one of the 4 radials. The considerable difference in diameter between the 10mm aluminum radial and the 1mm stainless steel rope means that the high impedance at the junction point allows only the lowest 40m band to flow through the rope (hence the Dual Band function), while the higher bands, e.g. 20m and above, function as before. The total length of the stainless steel rope, plus the length of the aluminum radial added together, form a single counterweight of approximately 1/4 wave at 40m, which is then folded over the 2

subsequent radials, reducing the bulk and avoiding the need to install uncomfortable wire radials.

o The lateral stubs like on the MV6 resonate on the higher bands17,15,12,10 and 6m. The MV7 is perhaps the only multiband feeded directly without the use of adapters or impedance transformers that would introduce losses and limit the applicable power, it is equipped with a high impedance inductor that creates a DC short circuit, dispersing to ground any disturbances caused by atmospheric events or electro-static discharges. The mechanics are refined and exclusive like all Grazioli products, the precision telescopic tubes are made of AW6063-T66 alloy, the fixing is done with quality clamps in AISl-316 stainless steel, the brackets, the screws, and the U-bolt and V-bolt are in AISl-304 stainless steel, the aluminum components are obtained from solid using CNC machines, the Stub crosses are in injection-molded thermoplastic material and protected against UV rays. It is supplied with a FAIR-RITE FT240-43 toroid, for the construction of an efficient Choke to be installed immediately under the connector, and a 3 way clamp for the wind bracing to be used in very windy areas. Support Italian excellence, our products are conceived, designed, and built 100% in Italy, made with artisan care, with attention to even the smallest details.