Force 12 CC&R Friendly

Customers have been asking us for several years for an effective antenna that would meet the often strict restrictive covenants in many housing developments. We looked around at what was available in the market and concluded there was nothing to meet the need. Many had nice VSWR's, but performance was terrible. We laid out a development plan, built and tested antennas of all types including loops, bent wire, parallel wire, compressed dipoles and verticals, coil loaded, end loaded and combinations of various types. Some probably would make you laugh! Overall, the antenna had to be efficient; otherwise, there was not much to offer, because even a lightbulb works! (See my article in QST July, 2000 entitled Everything Works.)

The antenna that originally emerged to meet the need for a low profile antenna was released in 1996: the ZR-3. This 6' tall vertical dipole for 20-15-10 meters was more than 90% efficient on all bands and was a new beginning. Built both for amateur and commercial customers, the ZR design proved to be an incredible low profile vertical antenna. The ZR is a balanced antenna, requires no radials (because it is a center fed dipole) and paved the way for further vertical dipole designs. The one short-coming of the ZR was that it was difficult to produce, requiring machined parts and/or welded sub-assemblies. This also meant it was a bit expensive and complex to assemble; however, it was an excellent solution and those with ZR's of all types have enjoyed its high performance.

Force 12 continued listening to customers, kept working towards the goal and announced the Sigma^© series in 2001, with the 5-band Sigma-5^© leading the way for low profile needs. The Sigma^© single and multi-band verticals are the result of comprehensive development and testing. The competitive and DXpedition results from various vertical dipoles and arrays further proved the effectiveness of the Sigma^© design. Our commercial customers all changed over to Sigmas.

Two Sigma^© models are ideal for restricted locations, but we did not stop there. After the fall of 2001, Force 12 used its expertise with aluminum and began building sectionalized flag poles. Realizing we had the capability to make the flag pole into an antenna, we added the insulating base and hardware to do it.

The Sigma-5^© is perfect for home and travel. It is assembled in minutes using stainless machine screws and wing nuts.The Sigma-5^© can be mounted in a bucket of cement, on a patio umbrella stand, on the ground and guyed once, on the roof - just about anywhere. Because the Sigma-5^© is a true vertical dipole and built symmetrically, it can be used horizontally, too.

SIGMA-5^{^©}
Full Band coverage: 20-17-15-12-10 Meters
NO Traps, True Vertical Dipole, No Radials
>90% Efficient all bands & 100% Pre-tuned
Rated at 1,200 w PEP SSB, 700w CW
2' Sections, Free Standing
Simple Assembly - NO Tools
9' tall, plus 18" Base Post
7 pounds
Perfect for home and travel
Complete with balun and 50' of control cable
All you need is coax and 12 volts @ 70ma
Options: additional control cable; X-base (2' sections); external base post

The Sigma-SV5^© is electrically the same as the terrific Sigma-5^©, but looks like a mast with a TV antenna on top. At 11' 11" tall, including the 4' tall base post, the Sigma-SV5^© draws little attention. We increased the diameter and wall thickness of all the tubing for for added strength so it can be mounted on the ground, roof, or chimney. Not the greatest TV antenna, but attach the Sigma-SV5^© feed line to your TV using a standard UHF-F coax adapter and you can watch local TV.

SIGMA-SV5^{^©}

Local channel 6

Full Band coverage: 20-17-15-12-10 Meters

NO Traps, True Vertical Dipole, No Radials

>90% Efficient on all bands & 100% Pre-tuned

Rated at 1,200 w PEP SSB, 700w CW

4' Sections, Free Standing

Simple Assembly using hand tools

11' 11" tall including 4' Base Post

11 pounds

Perfect for home: ground mounted, chimney mount, or guyed on the roof

Complete with balun and 50' of control cable

All you need is coax and 12 volts @ 70ma

Options: additional control cable; X-base (as shown in photo above, for temporary installation)

This antenna begins as the beautiful FP-15 flag pole. We then add a base post and base insulator to create the FPA-15 flag pole antenna. Made of 2" diameter aircraft grade aluminum, the FPA-15 comes in 4 sections, each 4' long, plus the base. All you need to do is add radials, a feed line and wind an RF choke as the coax enters the house. Punch the transceiver tuner button, or use a separate tuner and you are on the air! Efficiency is >90% on 20 through 10 meters. The FPA-15 can also be used on 30 and 40 meters with an efficiency of >80%. Taller, stronger flag pole antennas for low band operation are available.