Search results
Results From The WOW.Com Content Network
In the case of input and output frequencies in the United States, for example: Amateur repeaters in the 144–148 MHz band usually use a 600 kHz (0.6 MHz) separation, in the 1.25-meter band use a 1.6 MHz separation, in the 420–450 MHz band use a 5 MHz separation, and in the 902–928 MHz band use a 25 MHz separation.
These are effectively a higher-performance version of a diplexer, typically with a narrow split between the two frequencies in question (typically around 2%-5% for a commercial two-way radio system). With a duplexer the high- and low-frequency signals are traveling in opposite directions at the shared port of the duplexer.
Transformers, autotransformers, and baluns are sometimes incorporated into the design of narrow band antenna tuners and antenna cabling connections. They will all usually have little effect on the resonant frequency of either the antenna or the narrow band transmitter circuits, but can widen the range of impedances that the antenna tuner can match, and/or convert between balanced and ...
The 2-meter amateur radio band is a portion of the VHF radio spectrum that comprises frequencies stretching from 144 MHz to 148 MHz [1] in International Telecommunication Union region (ITU) Regions 2 (North and South America plus Hawaii) and 3 (Asia and Oceania) [2] [3] and from 144 MHz to 146 MHz in ITU Region 1 (Europe, Africa, and Russia).
Repeaters are found mainly in the VHF 6-meter (50–54 MHz), 2-meter (144–148 MHz), 1.25-meter band (1 1 ⁄ 4 meters) (220–225 MHz) and the UHF 70 centimeter (420–450 MHz) bands, but can be used on almost any frequency pair above 28 MHz. In some areas, 33 centimeters (902–928 MHz) and 23 centimeters (1.24–1.3 GHz) are also used for ...
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment ...
Basic automatic frequency control in a radio receiver. У = RF amplifier stages, Д = frequency discriminator stage. In radio equipment, Automatic Frequency Control (AFC), also called Automatic Fine Tuning (AFT), is a method or circuit to automatically keep a resonant circuit tuned to the frequency of an incoming radio signal.
The ports of a diplexer are frequency selective; the ports of a combiner are not. There is also a power "loss" difference - a combiner takes all the power delivered to the S port and equally divides it between the A and B ports. A diplexer does not. A diplexer frequency multiplexes two ports onto one port, but more than two ports may be ...