The S9v 18' Mk II is a tough, yet ultra-lightweight vertical designed for Amateur Radio use from 20 through 6 meters. The 18' Mk II is constructed of rugged tapered fiberglass, weighs under 2 pounds and is double insulated for the safety of your family and neighbors.
The design features UV-resistant, high-tech polymer tube rings that quickly slide on and off the antenna, allowing lightning-fast "tool free" deployment of the antenna at home or in any field environment.
The 18' Mk II can be mounted on the ground or on your roof.
steel pipe. The antenna base tube simply slips over the pipe for a simple and elegant deployment. (A mechanical connection from the antenna base tube to the pipe is neither required nor desired.)
- Permanent ground-mount installations require a 2 foot long, 1” OD MAXIMUM galvanized
normally used for TV antennas. In this configuration, the antenna functions as a ground plane (GP) antenna and four, ¼ wavelength radials are required for each band ofoperation.
- Because the 18' Mk II is so light, you can roof-mount the antenna using a simple 3' tripod
Since the 18' Mk II is close to a full quarter-wave vertical on 20 meters, it can be used as a superb 20 meter DX antenna using the antenna tuner inside your rig (or with an external antenna tuner in your shack). In this configuration, the antenna may be ground or roof mounted and fed directly with a high quality 50-ohm coaxial feed line. A 1:1 choke balun is recommended to prevent RF from entering your shack via the coax outer shield.
If you want to use the 18' Mk II as a multiband vertical, you will need an external antenna tuner in your shack and a 4:1 unun at the antenna feed point. Internal rig antenna tuners do not have adequate range to match the higher impedances presented by the antenna on frequencies above 20 meters. We recommend the LDG Electronics series of auto tuners for use with these products. LDG tuners easily handle the wide-range of impedances presented by the antenna over the higher HF frequencies.
A 4:1 unun lowers the higher impedances presented by the S9v on frequencies above 20 meters. Balun Designs manufactures two 4:1 ununs specifically for S9 antennas.
For optimum performance, a ground-mounted 18' Mk II should be used with at least 16 radials (32 preferred), with each radial at least 13 feet, 5 inches long (0.2 wavelength at 14 MHz). Actually, there is no precise formula to calculate ground-mounted radial length because everyone has different soil and soil tends to change the electrical length of the radials. However, a general rule of thumb for radials is: “longer” and “more” is better. If you have the time and resources, 32 or more radials each at least 13 feet, 5 inches in length (or longer) should be considered to ensure top performance. It is highly recommend that you use the optional S9 Radial Plateto connect and organize your ground radials.
PLEASE NOTE: FOR INTERNATIONAL SHIPMENT ADDITIONAL SHIPPING SURCHARGES MAY APPLY.