‘SUPER SCANNER 27 MHz Citizens Radio Base Station Antenna instruction manual ff FEATURING if OMNI OP ff DIREC TIONALTHE “SCANNER” PRINCIPLE ‘The “SCANNER” is a multi-olement dirsctional antenna system especially developed to be electrically rotatable for a full 360° in three 120° steps. This accomplishes the same results ‘ordinarily requiring mechanical rotation to point the gain pattern in a desired direction. With a single radiator and reflector system, the pattern appears as shown at right, Direction of Radiation By using two reflectors and one radiator, the pattern is extended and a greater gain, in ea © Rodictor gtagmesrcreesane, | ene at right. ‘As shown in the illustrations above, both systems require a mechanical means for rotating ‘the systoms in order to change the direction of “greatest gain”. This objective is reached by the "SCANNER" through an electrical system of rotation. The system consists of three elements, mounted 120° apert around a circle whose center is a triangular mounting bracket. Coaxial cables of predetermined fixed lengths connect each ele. ment to a relay switching meche ‘This switching mechanism is a relay assem- bly whose function is to switch the cables in such ‘mannor that one alomont becomes a radiator and. the other two become reflectors. This produces the desired results as shown in the drawing at the right and the deseription that follows: 9, A an Ors and the direction of radiation is shifted South- west. “The direction of radiation and the gain pat- tern is thus rotated ELECTRICALLY in three 120° steps.‘An OMNIDIRECTIONAL POSITION is also provided on the Super Scanner. In this position, all the lights are on indicating that all three elements plus a matching network or shorted ‘OMN! stub cable are connected giving a stand-by monitor position resulting in a properly matched antenna suitable for receiving and transmitting. A RELAY BOX, containing the relays which accomplith this electrical rotation, is mounted on the triangular mounting bracket. The relay essembly consists of three relays and color coded coaxial cables extending aut of the Relay Box and connecting to matching color coded slemants. A coaxial S0:239 connector is provided for the feed cable (not furnished) which connects with the transceiver. A terminal strip lettered A,B,C & D is provided to match a similar strip on the Control Box. ‘The method of assembly and installation is covered in the “Installation Instructions” found in this manual Four-conductor (coded) weatherproof cable is required (not supplied) to connect the terminai strips, A\B\C & D, matching same on Control Box. This proper matching is essential. Some versions do not have a terminal "C". In such case, disregard any reference for terminal “C” on RELAY and CONTROL. BOXES; only 3 3-conductor control cable is required. “The coaxial cables connocted to the relay assembly (Relay Box) act in duel capacities. When @ ‘coaxial cable is switched to one element as a fead line, the other two are disconnected from the transceiver antenna cable and act as stubs and enable the other two elements, which now act as re- tlectors, to be of proper electrical longth to do their reflecting job efficiently. These lengths must NOT be altered. Some versions have a fourth cable shorted at the end and covered with @ plastic cap; this tuned matching stub must NOT be altered either. ‘The CONTROL BOX, located at the radio operator's position, has a rotary control switch that determines the direction of radiation; indication is provided by three lights which can be labelled ‘corresponding to the proper directions, determined by orientation at the antenna in installation. Directionel labels are provided, in the hardwore kit, that can be applied near the corresponding lights. For the OMNI/MONITOR/STAND-BY feature, the control is placed in the position to light all the lights. ‘The operator selects each 120° segment by rotating the switch to the light indicating the desired direction. To locate the diraction of a received signal, rotate the switch for best signal reception while the distant station is transmitting, After an exchango of transmissions, the ‘switch may be returned to the Monitor position for omni-directional stand-by. OFF positions are provided at the ends of the switch segments; in these positions, the antenna is in the OMNI position and can be used, but all lights are extinguished. The circuitry of the control box is pro- ‘of the plugin transformer on the power cord, PRE-INSTALLATION HINTS: {tis important that the installer read the following pages; suggestions and methods given will assure easiest, most efficient installation. The use of a silicone grease which protects without inter- fering with electrical contacts, on threaded parts of the antenna, will help in keeping joints corro- sion free and facilitate future disassembly of the antenna, Besides the usual hand tools, other 6 of this manual tems needed to complete the installation are listed on page