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An RF switch or microwave switch is a device to route high frequency signals through transmission paths. RF (radio frequency) and microwave switches are used extensively in microwave test systems for signal routing between instruments and devices under test (DUT). Incorporating a switch into a switch matrix system enables you to route signals ...
The AN/URM-25 was part of a series of vacuum tube-based signal generators built for the U.S. military in the early Cold War-era.. Today they are collected and used by vintage amateur radio and antique radio enthusiasts who say they provide reasonably high accuracy and stability for a low cost, with build quality reflecting tough military construction requirements and standards.
Cable length limits the controller-device distance to two meters per device or 20 meters total, whichever is less. This imposes transmission problems on systems spread out in a room or on systems that require remote measurements. Primary addresses limit the system to 30 devices with primary addresses. Modern instruments rarely use secondary ...
The S stands for "Strength". Strength is an assessment of how powerful the received signal is at the receiving location. Although an accurate signal strength meter can determine a quantitative value for signal strength, in practice this portion of the RST code is a qualitative assessment, often made based on the S meter of the radio receiver at the location of signal reception.
In radio this device is also known as a dummy antenna or a radio frequency termination. It is a device, usually a resistor , used in place of an antenna to aid in testing a radio transmitter . It is substituted for the antenna while one adjusts the transmitter, so that no radio waves are radiated so that the transmitter does not interfere with ...
In testing of new electronic devices, a frequency sweep may be done to measure the performance of electronic components or systems. For example, RF oscillators are measured for phase noise, harmonics and spurious signals; computers for consumer sale are tested to avoid radio frequency interference with radio systems.
The combined test signal can be injected directly in to the receiver if the antenna is removable. A second directional coupler, connected in the conventional configuration, can be used to provide a feed of the input to a spectrum analyser. This allows confirmation that the input signal is free of intermodulation products.
Transmitters feeding a balanced transmission line will need a balun. This transforms the single ended output of the transmitter to a higher impedance balanced output. High power short wave transmission systems typically use 300 ohm balanced lines between the transmitter and antenna. Amateurs often use 300–450 ohm balanced antenna feeders.