FISHING POLE ANTENNA

                                                                      

The construction is the same as is used for fishing poles. Each of the 7 hollow tubular metal sections has a plug one end and a socket on the other end. All the sections are connected by a string made of either a cloth or metal cord. At the bottom of the base element there’s a spring inside the tube to tension the cord. This way all the elements are kept in order when they are disconnected from each other and are held together when assembled  into a  113.5”(2.88 meter) long antenna. When an 8” long base is added the overall length is 121.5”(3.09 metres). When disassembled the package is only 17 inches long. 7 sections times 17 inches is 119 inches, but the plug end go into the socket ends so the overall length is shorter than 119”. There are some web pages that erroneously give the length as 7.5 feet.

  The AB-591 Antenna base has a male 3/8-24 thread which is the same as is used on most ham radio and CB antennas. The base also has a cnter pin that actuates the antenna switch in the PRC-25 or PRC-77 radio to switch from the BNC 50 Ohm output to the whip antenna.

HOW TO USE

Since the spring is at the bottom of the lowest antenna element you want to avoid jamming it’s operation. This means that when assembling the antenna you start with the top section. This way the spring is not trying to pull the string around joints are open

By opening a joint and folding the top setions of the AT-271 down beside the lower sections and tying them together you can make a number of different lenths of whip antenna. Using this method you can easily match the AT-271 to the frequency of operation.

Experimentation is needed here using the 4395A network analyser to see what bandwidths are possible for each of the above configurations. Then a range of frequencies could be given for each one