7 Connector Care
Making Connections
Making Connections
Good connections require a skilled operator. Instrument sensitivity and coaxial
connector mechanical tolerances are such that slight errors in operator technique
can have a significant effect on measurements and measurement uncertainties.
The most common cause of measurement error is poor connections.
Connection Procedure
1. Ground yourself and all devices (wear a grounded wrist strap and work on an
antistatic mat).
2. Visually inspect the connectors (refer to Visual Inspection).
3. If necessary, clean the connectors (refer to Cleaning Connectors).
4. Carefully align the connectors. The male connector center pin must slip
concentrically into the contact fingers of the female connector.
5. Push the connectors straight together. Do not twist or screw them together. As
the center conductors mate, there is usually a slight resistance.
6. Do not twist one connector into the other (like inserting a light
bulb). This happens when you turn the device body, rather than the
connector nut. Major damage to the center conductor and the outer
conductor can occur if the device body is twisted.
7. Initial tightening can be done by hand or with an open-end wrench. Tighten until
"snug" or where the connectors are first making contact. The preliminary
connection is tight enough when the mating plane surfaces make uniform, light
contact. Do not over tighten this connection.
At this point, all you want is for the outer conductors to make gentle contact on
both mating surfaces. Use very light finger pressure (no more than 2 inch-pounds
of torque).
8. Relieve any side pressure on the connection from long or heavy devices or
cables. This assures consistent torque.
9. Torque the cable or device to the final value using a torque wrench.
Getting Started and Troubleshooting Guide 93