Excerpts from reviews of the Sommer multiband beams
Lew McCoy, W1ICP, author of the book "Lew McCoy on Antennas" (CQ Communications, Inc., Hicksville, New York), writes on page 85 about his XP50 series Sommer beam:
- ..."Frankly, I have always considered this to be an ingenious antenna from several aspects. ...On 20 meters the three elements produce a typical three-element gain of 7-plus dB."
He then notes that these elements become 5/8 wavelength long on 15 meters and that the 20-meter elements become full-wavelength elements on 10 meters. (Please note that all gain figures are given in comparison to a 1/2-wavelength dipole.) The electrical layout of the antenna means that it is a >6 element system at 10 and 12 meters, and a 3-4 element system on 15 and 17 meters.
Lew held several posts at the ARRL over a period of more than 30 years. He retired there as Technical Editor. He has been using a Sommer XP50 series beam since 1984.
- From Jim Godron, N1EJF, published in 73 Magazine, April, 1987, on his XP707:
- "The operating principle of the DJ2UT antenna is quite remarkable. On 20 meters, the system is a full-size beam using 1/2-wave elements without traps. The main difference between this system and others is that all elements are driven with a phasing line. In effect, you have a 4-element log cell that develops an impressive 9 dB of gain and an excellent front-to-back ratio."
- "All the gain figures presented for this antenna are as compared to a 1/2-wavelength dipole, not to some mythical reference (the figures presented are the manufacturer's claim, but my experience is that his claims are conservative)."
- "As I was assembling this antenna, the one thing that became clearer and clearer was the quality of the materials and engineering. ...The element holder castings are massive, weighing several pounds each. Every piece of this antenna is first-rate and designed to last a lifetime. All connecting pieces, U-bolts, nuts and bolts are stainless steel."
- "This beam performs as well as monobanders. While its cost may at first seem high, it is actually very reasonable when compared with what you would have to spend to get comparable performance with other antennas."
- "If you're serious about DX, appreciate quality, or want an antenna that you can leave to your children, you should give serious consideration to this system."
- From Lew McCoy, W1ICP, CQ Magazine, April 1986:
- "When I did SWR curves for each of the bands, I found that mine, in most instances, were better than those shown in the manufacturer's advertising literature."
- "All the gain figures are measured over a half-wave dipole, not some mythical, make-it-look-good reference."
- "The boom is made up of two lengths of square aluminum tubing in order to provide additional strength plus added flexibility. Having such a boom is a rather radical departure from the customary aluminum tubing. However, Sommer has excellent basic engineering here in that the boom can flex and stretch, similar to a suspension bridge."
- "I was also constantly amazed as to how low the SWR was across 20, 15, and 10. If I sound enthusiastic about the XP506, I am, and I will really be surprised if this system doesn't revolutionize multiband beam antennas.
Sommer Antennas
P.O. Box 710
Geneva, FL 32732
Phone: (407) 349-9114 | Fax: (407) 349-2485
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