Products & Product Reviews

Is an HF Vertical Antenna Right for Your Amateur Radio Station (Part 1)? DX Engineering THUNDERBOLT® Dual-Band High Performance 40/30M Vertical Antenna

In our first installment of OnAllBands’ overview of DX Engineering HF vertical antennas, we’ll be highlighting the 40/30M THUNDERBOLT® model. But first, let’s look at the big picture: Is an HF vertical antenna the right choice for your station? Here are a few points to consider before the antenna’s concrete base starts to harden in your backyard:

  • Probably the most noted attribute of HF vertical antennas is their omni-directional radiation pattern. With an extensive system of radial wires installed at its base, an HF vertical antenna can deliver excellent performance comparable to a horizontal dipole.
  • HF vertical antennas have a superior low-angle radiation pattern, making them ideal for long-range DXing. However, they wouldn’t be your first choice for making short-range contacts closer to home.
  • We can’t emphasize this enough: If you want true HF performance, don’t skimp on deploying ground radial wires. Think you’ve gone overboard? Add some more and monitor how your antenna performs. Hustler BTV Series 4-, 5-, or 6-band verticals are great examples of antennas that vastly improve with a radial system in place. Check out DX Engineering’s Hustler BTV manual for in-depth instructions and advice on adding a radial system to your quarter-wave vertical antenna. If getting on your knees to run wire isn’t your cup of java (or you can’t find someone to do it for you), you might want to consider another option.
  • HF directional beam antennas (when positioned correctly) will typically perform better than an HF vertical. However, low-profile verticals are less likely to draw the attention of neighbors who may not appreciate the sight of a sprawling 32-foot, 8-element Yagi outside their bedroom window.
  • HF vertical antennas come in either monoband or multiband varieties. Multiband HF verticals often employ traps (e.g., Hustler BTV Series, DX Engineering THUNDERBOLT® 80/40M) or loading coils (e.g., Butternut Antennas) on the vertical element. The loading coils or traps (paralleled tuned circuits) electrically add or subtract to the length of the antenna based on the frequency of the signal. The use of coils and traps allows multiband verticals to remain relatively short. In the case of DX Engineering’s 160M monoband vertical, a capacity hat adds horizontal elements that help keep its length to a manageable 55 feet.
  • When used in a multi-vertical array, verticals can even provide low-band directivity.
  • HF vertical antennas make good choices in tight areas. Those that are self-supporting, such as the DX Engineering THUNDERBOLT® 80/40M and 40/30M antennas, require no guying and even less space. For some verticals, Hams can choose from ground- or roof-mounted options.

If you’re not sure which HF vertical antenna is right for you, ask the Elmers at DX Engineering for guidance based on your Amateur Radio interests, space requirements, and budget. They’re well-versed on DX Engineering’s complete lineup, including today’s featured model—the THUNDERBOLT® 40/30M Dual-Band High Performance Vertical Antenna.

This antenna, measuring an optimal 30 feet, provides full band coverage on 40 and 30 meters. It’s tunable to operate with an SWR of 1.5:1 or less across both bands. The maximum power rating ensures solid performance, particularly on CW. Plus, Hams can enjoy improved activity in digital modes, which are popular on 30 meters.

The massive EXTREN® channel insulator supporting the rugged structural-grade 6063-T832 drawn aluminum antenna radiator has over twice the tensile and flexural strength of competitive nylon plastic materials, in addition to its superior RF handling characteristics.

Other features:

  • 40M bandwidth greater than 750 KHz with SWR under 2:1
  • Tunable above and below 7 MHz range for MARS and CAP frequencies
  • Maximum legal power handling
  • DX Engineering’s patented Tilt Base, stainless steel hardware, element clamps, and mounting plate included
  • Self-supporting design withstands 60 MPH winds without guying

DX Engineering recommends the installation of a radial system of 32 radials, each 32 feet long. Fewer radials will work but with diminished results. For detailed installation instructions, other items you will need (steel mounting pipe, tubing, and concrete, et al.), and suggested parts, read the instruction manual.

What do Hams think?

Five Stars: Very well built. Tilt base makes installation and tuning a breeze.

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