HF 1/4 Wave Verticals
Magnum-160VX2 - $ 2449.00
The Magnum 160-VX2 is an electrical quarter wave vertical for the 160 meter band. It can be tuned over a wide frequency range, approximately 1.780 – 1.950 MHz. It is physically about 62’ tall and can be mounted at ground level, or elevated. The loading used is a high Q, air-core, base-loading coil, made of 3/8” diameter aluminum tubing, wound on a 5” diameter form. The Magnum 160-VX2 is designed to present a low profile and withstand winds in excess of 90 mph. It needs to be guyed only once using non-conductive line and comes with one set of welded guy ears. The Magnum 160-VX2 is constructed of both thick wall and thinner wall tubing in a tapered design. The base is a hinge mount made of ½” thick aluminum plate. The base loading coil is a manually-tuned Tornado unit that physically expands and contracts the coil. A motor drive Tornado is optional for remote tuning.
The Magnum 160-VX2 is insulated from the aluminum base using large diameter solid, pultruded fiberglass rod. It is fed with 50 ohm coax through either a 1:1 balun or RF choke. It is matched using a helical hairpin (copper coil) placed across the feed points. Two (2) full length, elevated radials should be used. An extensive buried radial system can also be used to reduce the near-field losses of the entire antenna system.
The radials are the current return for the vertical antenna. For this purpose, the most efficient is to have them elevated above the ground. This technique de-couples the radials from the ground, which minimizes ground losses. Through real-time testing, the radials should be elevated about 16’ above the ground.
The Magnum 160-VX2 is very efficient due to the large diameter and high Q loading system, although the antenna is less than 50% of full size. With the antenna matched and using two (2) elevated radials, the expected 2:1 VSWR bandwidth is on the order of 42 kHz.