Improve the performance of your A99 antenna with this replacement top section
Upon examination of the A99, it will be clear that the majority of design work went into the lower and center sections. The upper section, basically a straight piece of wire encapsulated in fiberglass, is cut to length to make the entire unit resonant in the 11-meter CB band. In order to accomplish that, the upper section, as a stand-alone antenna, resonates at about 32.650 MHz.The FS-99 was designed to improve the performance of the A99 CB base antenna. We drew upon our 25 years of knowledge in the manufacturing process of high performance wire wound antennas. In short, there are three key factors that make the helically wire-wound antenna a better choice.
First of all, it is common knowledge that a top loaded antenna out performs base, center or continuos load antennas.
Secondly, when you feed the base of our antennas with a relative high current to voltage ratio, as the current slows due to the electromagnetic resistance created in the loading coil, the RF voltage radically increases. Increased voltage relates to increased performance.
Thirdly, unlike other designs, the helical design of the FS-99 lowers the angle of radiation, in effect keeping more of the transmitted power at ground level. By replacing the A99 upper section with the FS-99 you end up with three pieces of engineered antenna instead of two.
The FS-99 is a heavy-duty (core diameter = 0.375” or 10mm) fiberglass antenna that is helically wound to perfection with double insulated 19 gauge copper wire. The mounted length of the FS-99 is 5 feet (153cm). It is covered with white UV stabilized PVC shrink tubing and topped with a white tip. The base has U.S. standard 3/8”-24 threads. The FS-99 is topped off with our patented tunable tip mechanism. Even though the A99 has a tuning ring of its own, we choose to add the tunable tip to expand the possibilities of the antenna. The tunable tip on the FS-99 allows it to be center frequency tuned from 31.650 to 33.650 MHz. Coupled with the A99 tuning ring, this extra 2 MHz of range expands the usable frequencies.
After completing our design, and before introducing the FS-99 to the marketplace, six months of field tests were conducted. Tests were done by CB’er’s in the general public in various locations and under various conditions. Performance increases in the 15 to 35 mile (25 to 55 kilometers) ranges were chosen as the focal point of data gathering. Reports on communications within the sample range showed a consistent increase of 1 to 2 “S” units of improvement on both transmit and receive. A reduction in background hiss was also noted. Also, due to the change in radiation angle, skip condition changes were noted. As expected, when changing from the FS-99 to the original radiating element, some stations were lost while others were gained. In several cases, users utilized two A99 antennas, one in original form and the other with the FS-99 replacement radiator. With the use of a switching device they could easily monitor the performance changes to stations that were within the non-skip range of both antennas. At the same time, skip communications to various stations that fell within the signal bounce localities of each antenna were achieved with the flip of a switch. For those not familiar with the skip conditions affecting CB communications, it is improper to base an antennas performance solely upon skip communications. As in billiards, the angle of departure directly affects the angle of bounce. Antennas with different designs have a different angle of radiation. Accordingly, it is very likely that station to station skip communications will be affected.
