The IBA-5 Indoor CB Antenna was introduced to the market in 1989. This product was an upgrade to the original antenna (IMB-5) that Firestik introduced in 1977.
The Firestik indoor antenna was designed for two basic reason: (1) to allow CB radio operation where outside antennas are not allowed or, (2) for the CB’er who does not want to put up an outside antenna. In either case, the operator should be aware that this type of antenna is normally a compromise between rules, space and optimum performance. In most cases the performance will not match that of a good outdoor antenna. However, in many instances, the indoor antenna by virtue of its elevation, as well as the scattering effect the building has on its radiating field, has been known to out perform antennas of equal design on a vehicle at street level. Excellent performance can be recognized in spite of absorption by various building materials. DX’ing (long range communications) may not always be possible but is certainly a reality.
Indoor convenience is not without its limitations, and some compromise. An awareness of possible restraining conditions (e.g. building design, construction materials etc.) under which the antenna will be expected to perform can be appreciated more for an intuitive approach rather than an endless list of do’s and don’ts. With respect to indoor base antennas, the Firestik Indoor Base Antenna has gained a reputation for unexcelled performance. You should not let its limitations deter you from using it. When you are in a situation that limits your choices down to indoor antennas, be confident that the Firestik Indoor Base Antenna will satisfy or surpass most persons expectations of how it should work. Keep in mind that it was specifically designed to work indoors.
The radiating element is a five-foot Firestik II type antenna with our patented tunable tip mechanism. The core is 3/8″ fiberglass wound with 19ga double insulated magnet-wire. The antenna base is made of chrome plated 1/2″ hex brass stock and has standard 3/8″-24 threads. The assembly is covered with white PVC shrink tubing.
The hub is a centrally located assembly that allows the antenna, coax and radials to be connected together. It is made up of two 2″ circular metal disks, one upper and one lower. The upper disk has the coax and antenna coupling nut attached and the lower disk is used to connect the four ground plane radials. The disks are mounted directly above each other with 3/4″ stand-offs.
The coaxial cable supplied with the kit is 18ft (5.5m) RG-58A/U. This is high quality, stranded center conductor coax with average shielding in the 95% plus range. A standard PL-259 connector is installed on one end of the coax for connection to the radio. The antenna end of the coax has our exclusive Fire-Ring connector for trouble free operation.
The ground plane for the IBA-5 is supplied by four (4) 1″ (25mm) x 30″ (76cm) flat steel radials. The radials are covered with black PVC shrink tubing and have a protective vinyl tip on the outbound end. At the hub end of the radial, a small hole is placed in order to secure the radials to the hub assembly.
Unfortunately, indoor antennas will not, and can not be expected to radiate energy at high radio frequencies through all metal buildings. Buildings of all steel construction (top and sides), resting on earth or concrete slabs, can be expected to reflect virtually all incoming and outgoing transmitted energy without penetration. Buildings with steel siding resting on earth, but with wood frame roofs that are covered with wood shingles, composition or tar paper will allow radiation, but largely upwards. Some outwards radiation from the effects of