Antenna Mounting Hardware (800's)

Section 800 Content Consideration

The first sub section is Tripods, Extensions and Probe Mounts. The full catalogue or Web site will inform you of the size and various interconnect threads. We have tried to provide an interface to nearly all the known EMC antenna manufacturers. For any given antenna first decide at what height you will require the device to be mounted relative to the surface over which the measurements are to be made. It is most likely the antenna will have to rotate through 90 degrees to satisfy the polarisation requirement. If you have ordered just a tripod, check to see if the antenna comes with its own vertical support rod which would allow it to change polarisation from its position on the tripod. Bilog antennas are particularly prone to this problem with their large “bow tie” elements having insufficient clearance from the support device when vertical. Most of our devices are manufactured from either delrin or fiberglass with the exception that some of the heavy duty tripods have wooden legs. We have designed all the interfaces around three main screw threads. These are ¼ UNC (camera thread); 5/8 UNC and 7/8 UNF.

Under the Sub Section: Masts, Turntables, Positioners and Controllers we offer a broad selection of OATS hardware. If choosing a mast, there is a choice of the manually controlled with a wind-up winch at the base. If using the manual version for scanning an antenna between 1-4   metres, an assistant will be required at the mast base. Automatic masts will require 240vac at the mast location for operation although the control is through a fibre optic to a controller up to 20 metres away. With the automatic mast (item 822) a controller must also be hired either in the form of a simple hand controller (item 822A) or an electronic readout device with front panel control & GPIB interface. With all types of mast please let the Hire dept know if the mast is to be stationed outside or within a chamber. For outside stability the mast can arrive with either three guide ropes to secure the mast top to the ground and or four outriggers which secure to the base of the mast and effectively create the stability of a 2 metre square base. With all masts the antenna will be mounted onto a 50cm (2”) square horizontal fiberglass boom. To this there are two main adaptors. One is an EMCO delrin plug which feeds through the holed boom and secures a series of antenna mount interfaces via either a ¼ UNC or a 7/8UNF screw. The other method is via item 841 or 842. This is an original EMCO device which slides along the boom until locked from underneath and then presents a 1/4UNC screw to secure the antenna mount interface. The last sub section dealing with clamps offers a range to suit most makes. The only practical turntable we can offer for hire is the 1.2m dia EMCO 2065 Lo-Pro. Again, 240vac is required to drive it with either a hand controller on a 2 metre lead or the full GPIB controller. For those customers who were familiar with the older EMCO 1050 series of mast, one of these is offered under item 821. The last piece of chamber hardware is the automatic sixteen point PP-01 probe positioner for the EN61000-4-3 field uniformity test. Although battery driven within the chamber it is fibre optically controlled via an SI-200 which comes with the item. These are always delivered by a competent member of the hire staff who will rig the positioner & instruct the end user on its operation. A recent addition is item 826 the MTT-01 or raised manual turntable. This device is in delrin construction with a circular base plate of diameter 0.8Metres. Mounted on the base is a telescopic vertical post supporting another flat circular delrin table of 0.6 metres diameter on which the EUT sits. There is a continuously rotating joint inserted between the telescopic post and the upper table. A continuously variable height is attainable from 0.6m to 1.3m in height. Bearing in mind that large wooden structures like raised tables are no longer accepted in anechoic environments and stacked cardboard boxes with EUTs on top are not exactly photogenic if appearing in a report, this could be a more acceptable method of supporting your EUT.

The last sub section is: Antenna Clamps and Adaptors We have endeavored to provide as many plastic screw interfaces as possible for all the known antennas. If in doubt discuss it with a technical member of the hire department.