Andrew Institute® - FAQ
Q. Can you use Andrew connectors on other manufacturer's cable and vice versa?
A. Andrew manufactures connectors to fit the dimensions and tolerances of Andrew cable products to ensure optimum electrical and mechanical performance. Andrew cannot control the dimensions and tolerances of other manufacturers products, and therefore, we cannot predict or guarantee performance. Andrew does perform some testing of its connectors on competitor's coaxial cable if specifically requested to do so by a customer. There is usually a fee to conduct this testing. The results only apply for the serial number of the cable tested and are not guaranteed by Andrew Wireless Solutions in any way.
Q. Can you use Andrew HELIAX fire retardant jacketed cable outdoors?
A. Yes. These products have UV stabilizers in them and carry the same warranty as the standard black jacketed cable.
Q. Why is weatherproofing required when Andrew claims connectors are 100% waterproof?
A. Connectors are supplied with O-rings and gaskets to provide a moisture barrier. When placed in their correct locations and the connectors are torqued to the specified levels, the connector is in fact 100% weatherproof. However, temperature changes cause metals to expand and contract which may cause threaded components to loosen. Additionally, wind loading creates vibration, which can also cause threaded surfaces to loosen. The installation of connection protechtion helps dampen vibration and prevent lossening parts to keep moisture sealed out.
Q. Why is it necessary to torque connectors to specific values?
A. Clamping and coupling torque values are specified to optimize the mechanical and electrical contacts. Over and under torquing connector components will adversely affect the mechanical and electrical performance of the connector. Coupling torque levels are specified by interface type and are consistent regardless of manufacturer. Clamping torque values differ greatly by connector design. Both values are specified on the Installation Bulletin provided with the connector.
Q. Is the silicone grease in connector kits used to enhance the seal of the connector?
A. No. The silicone grease is provided to lubricate O-rings and gaskets during the connector assembly process. The silicone prevents O-rings and gaskets from becoming damaged and pulled out of position.
Q. What are cable selection criteria when choosing the proper cable for my site?
A. Frequency, length, attenuation (link budget), flexibility, and average power handling are the criteria by which cable is chosen for a particular installation. It all comes down to size and performance vs. cost. The larger diameter cables provide better attenuation and power handling performance, but they cost more than a smaller diameter cable.
Q. Can connectors be re-used?
A. Yes, the connectors can be re-used without replacing any parts as long as no visible damage is done to the o-ring seals or center contact pins while removing the connector. Andrew recommends all subsequent connector attachments be performed on a freshly prepared cable end. Earlier designs may need replacement O-rings, gaskets and inner connector pins to restore the connector to a working condition. Replacement kits are available from Andrew.
Q. Why is it important to keep the grounding wire (earth lead) from the ground strap as straight as possible?
A. Keeping the grounding wire routed straight down toward the earth provides the lowest impedance path to ground to remove lightning transients as fast as possible. A long wire or one with a lot of bends will be slower to conduct lightning current to ground than a short straight one.
Q. What is an RPE (radiation pattern envelope) and how does Andrew derive the data?
A. Once an antenna design has proven to be uniform and consistent in the manufacturing process, a number of antenna's will be tested to assure consistency and repeatability in their pattern performance. The antenna's are measured for their total range at three points, bottom, mid, and top of the band. These measurements are done in horizontal and vertical polarizations. We also test for co-polarization and cross-polarization discrimination. The RPE is then generated based on this pool of data to assure that any antenna will meet or exceed the RPE performance criteria as proven for a particular antenna.
