In receivers, the process of converting the desired RF frequency results in an undesired sensitivity at a second RF frequency, which is referred to as the image frequency. RF filtering in the receiver is relied upon to reduce to acceptable levels the receiver's susceptibility to spurious RF signals at the image frequency.

The measure of a receiver's ability to reject signals at its image frequency. Normally expressed as the ratio, in dB, of the receiver's sensitivity at the desired frequency versus the sensitivity at the image frequency.

An expression of the opposition that an electronic component, circuit or system offers to AC or DC current. Impedance contains both resistive and reactive components, although generally only the resistive part of the circuit is usually quote in specifications as Ohms. So the higher the resistance, the higher the impedance.

To restore a piece of equipment to its factory default settings.

A connector at a particular point of a circuit that allows for the introduction of a piece of external equipment, so that the original signal now flows and is processed by the external equipment prior to being returned back into the original circuit.

A measure of the inter-modulation performance of a RF devices. Devices with high intercept points will generate lower levels of undesirable inter-modulation products as compared to similar devices with lower intercept points.

A process that can result in distortion. Inter-modulation is the result of two or more frequencies inter-reacting with themselves and generating new frequencies that are not present in the original signal. These are invariably based on the sum and difference of the original frequencies.

The process in IT (information technology) that requires near exact timing coordination to successfully transmit information, such as video or audio data. Isochronous data transfer ensures that data flows continuously and at a steady rate so that the receiving mechanism can display the result without interruption.

An isotropic radiator is a transducer that produces useful electromagnetic field output in all directions with equal intensity, and at 100% efficiency. In wireless applications the isotropic radiator is theoretical, although the dipole antenna roughly approximates it. It is used as a standard reference source against which the performance of other antennas is measured.

A physical controller that allows a tape machine's transport to move tape back and forth a small distance to find an edit point. Originally used by video editors to find an exact location on tape, jog wheels can be found on audio control surfaces to provide similar functionality within a digital audio editor.