Band (Mhz)	7	10	14	18,1	21	24,9	28	50
Gain (dB/D)	0-2	4	7	7,5	8	6	9	5
F/B- r	5	10	25	25	20	15	20	20
V -3dB Horiz	90	80	65	60	60	55	55	55
V -3dB Vert		120	85	85	70	110	80

Active Elements : 20 m (3elts) 3x driven full size (1/2 wavelength) elements LOG-1 + LOG-2 + LOG-3 15/17 m (5elts/4elts) 3x extended 1/2 wavelength plus elements about 5/8 wavelength long LOG-1 + LOG-2 + LOG-3 + EL-1B on 15 m + EL-1C on 17 m 10/12 m (7elts/5elts) 6 x 1/2 wavelength collinear elements 2 x 3 side by side LOG-1 + LOG-2 + LOG-3 + EL-1A + EL-2A + EL-3A + EL-1B as 3/8 radiator 30/40 m (1.5elt/1.25elt) All driven elements LOG-1 + LOG-2 + LOG-3 + EL-1B + EL-1C + EL-3A as "C"
NOTE : Well-built multiband beams with driven elements have a 1-2 dB higher gain than conventional systems with the same boom length and bandwidth (better element illumination). Remember, a 3-element monoband beam has 4 to 6 dB/D (see ARRL Antenna Book). The XP50 series beams are designed for the amateur with all-out performance in mind. Although the boom length is only 15 feet, XP 50s have easily outpaced much larger, conventional antennas in careful testing. The key is the total elimination of traps, which rob performance from even the largest of multiband antennas. Because of their high efficiency, XP50 series antennas suitably replace 3- and 4-element antennas of conventional design. For the 15 m (and 17 m) bands, three directly fed 5/8-wave elements in conjunction with elements 1B and 3A form a typical band gain of 8 dB/D. Operation on 17 meters requires an optional 8.2 (26 ft) element at boom location Z which does not influence the 10-20 settings but has the same properties on 15 meters. All elements are working on the 10 and 12 meter bands and contribute to a 8 dB/D gain. Coaxial stub housed in a plastic bax enables operation on the 30 m band without any mechanical extension. Using this configuration, the typical gain is about 2 dB/D. The 40 m band is activated by use of an individual power coil mounted at Y, which yields a 0 to 2 dB/D gain on this band
The XP-507 beam is an intermediate sized beam designed to replace conventional 3- and 4-element antennas. Although the boom length is a modest 4.4 metres, superb performance is obtained through the TOTAL elimination of L/C traps. Former trapped-antenna owners immediately notice increased signal reports, broader gain and SWR bandwidths, and f/b ratios that are good across the entire band – not just over one small sector. The XP507 covers 10, 12, 15, 17, 20 ,30, 40 meters bands. To maintain high performance, the DJ2UT antenna is fed with a model UT-2000 balun. This is an air-core device made from high-voltage, Teflon dialectric coaxial cable. With no ferrite core to saturate, this balun will handle 2 kW output without heating and the beam is rated above maximum legal power – regardless of mode or band. The XP507 antenna is built to very high standards of strength. Aircraft-quality aluminum tubing is used throughout, and all hardware is made of stainless steel. High-quality materials, combined with precision German craftsmanship that ensures that this Sommer antenna will provide many years of maintenance-free performance. Working Principe : 20 Meters On this band the DJ2UT multiband beam system is a full-sized beam utilizing 1/2-wave elements without traps. The primary difference is that all elements are driven via a phasing line, in a fashion similar to the log periodic. This technique provides "monoband" gain or better without the narrow bandwidth commonly associated with such antennas. As on all bands, the compromise between forward gain and f/b ratio has been optimized for amateur use through actual on-the-air testing and not random selection. 15/17 Meters Because the 20-m elements are approximately 5/8-wave long on these bands, the resulting high feedpoint impedance must be compensated for. Instead of resorting to "power-hungry" L/C traps, DJ2UT utilizes the capacitance found in the phasing line, in combination with another unique approach. Clustered about the feedpoint are 3 or 4 elements (depending on antenna model) in close proximity to each other. This combination of parasitic and driven elements simply and effectively brings the system impedance down to the desired 50 ohms. In addition, a special means of feeding the elements reduces the unwanted side-lobe radiation common to 5/8-wave systems. 10/12 Meters Since the primary elements of this design or 1/2-wavelength on 20 m, they are approximately a full wavelength on 10 and 12 m. In the DJ2UT system, they are fed via the phasing line as "split" f-wavelength elements in a collinear fashion. This configuration also presents a high feedpoint impedance. As on 15/17 m, this high value is reduced to 50 ohms by the influence of 3 or 4 elements in close proximity, along with an auxilliary 12-m element. 30/40 Meters By ignoring all elements but the longest (found at the rear of the boom), we may consider the DJ2UT antenna a simple dipole with a transmission line attached. Since this element, or dipole, is only 11.6 m (approx.) long, it is too short to be resonant on either 30 or 40 m and presents a capacitive reactance at these frequencies. On 30 m, the problem is solved by the simple addition of an L-C match. Similarly, 40-m compensation is achieved with a coil and/or coaxial capacitor. Since these networks are not in series with the antenna and only serve to cancel the "blind" reactive components, the problems of L/C trap loading are again avoided. It should also be noted that on 30 m, the 3- or 4-element cluster at the feedpoint serves as a director--providing some gain and a cardioid directive pattern in the larger models. On 40 meters, the mounting height of the antenna determines which element serves as radiator. As a result, the major radiation pattern may be in front or in back of the antenna, or even under 90 degrees, depending on antenna height. 6 Meters Option Easy, you just have to fit under the shortest element in front of antenna a 2.95m long tube. You can add some directors spaced approx 0.8m and increase gain without any disturb on others bands... that's magic like the magic band ! XP507 XP508 Caracteristics
DJ2UT Antenna XP-507 (XP-508 with 6m kit)
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