Transcript
Cable Handling Recommendations Radar and RF Microwave Coaxial Cable Assemblies Instruction Sheet 2016 The most important thing we build is trust
• •
• •
Securing the connector interface: do not use pliers! To ensure proper thread engagement and minimize the chance of cross-threading, first finger-tighten the connector interface. Most connectors are provided with wrench flats. A torque wrench should be used to tighten the connectors to the torque specified, insuring uniform repeatable connections. When tightening, turn only the coupling nut, preventing the connector body and the entire cable assembly from rotating. Maintain as large as bend radius as possible When using the cable in a confined area, maintain as large a bend radius as possible. A large radius reduces wear on the cable, and minimizes the electrical phase shift changes introduced by bending. If possible, form the bend over a smooth surface. Never crimp or kink the cable. The bend radius should not be less than 5 times the cable diameter. A smaller bend radius may cause changes in impedance and possible permanent degradation in electrical performance.
Special Handling • Don’t expose cable to temperatures beyond specs. • Don’t use the cable assembly as a tow rope or suspension wire. • Use Kellems grip to move cables (especially longer lengths). • Don’t stand on cable. • Don’t place or drop heavy equipment on cable. When the cable is subjected to localized compressive forces, the circular cross section of the cable is distorted, changing the characteristic impedance and thus VSWR. • Do inspect the cable assembly regularly. • Never route the cable over sharp metal surfaces which could cut into the RF coaxial cable. • Choose proper diameter cable clamps that do not “crimp” the cable. The Connector Interface Keep the connector interface clean to minimize wear and maintain performance. A lint-free swab or soft brush dipped in alcohol is the simplest and preferred method of cleaning the interface. Do not use Halide cleaners because they damage the support bead used in 7-mm connectors. Chips or foreign matter may be blown out of the interface with dry, non-oily compressed air. Be sure the cleaning agent has evaporated before proceeding to mate connectors. For Long Life and Consistent Performance • Don’t poke screwdrivers or other tools into connector interfaces. • Check the pin height regularly. Refer to MIL-PRF-39012 and MIL-STD-348 for proper dimensions. An out-of-tolerance pin height is a sign of a damaged connector, which should be replaced. • When mating two connectors, do not cross-thread the coupling nut. • Cross-threading damages the threads and/or breaks the contact finger tangs and is a common cause of connector failure. If difficulty is encountered when making a connection, remove the cable assembly, identify the problem, and correct it.
Cobham Advanced Electronic Solutions Integrated Electronic Solutions 11 Continental Drive Exeter, NH 03833 USA Tel: Email:
1.603.775.5200
[email protected]
www.cobham.com
