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In same-band repeaters, isolation between transmitter and receiver can be created by using a single antenna and a device called a duplexer. The device is a tuned filter connected to the antenna. In this example, consider a type of device called a band-pass duplexer. It allows, or passes, a band, (or a narrow range,) of frequencies.
Reflective array 'billboard' antenna of the SCR-270 radar, an early US Army radar system. It consists of 32 horizontal half wave dipoles mounted in front of a 17 m (55 ft) high screen reflector. With an operating frequency of 106 MHz and a wavelength of 3 m (10 ft) this large antenna was required to generate a sufficiently narrow beamwidth to ...
UHF: 225 TO 399.975 MHz Estimated Range: 5–20 km (3-12 mi) Dependent on conditions. This is the approximate range when not connected to a repeater or a network. Power Output: 2W to 10W Power Source: BA-5590/U non-rechargeable or BB-2590/U and UBI-2590 rechargeable batteries. Antenna: These units use the MPMP100X4 antenna (NSN 5985-01-184-0035).
Inherently an antenna diversity scheme requires additional hardware and integration versus a single antenna system but due to the commonality of the signal paths a fair amount of circuitry can be shared. Also with the multiple signals there is a greater processing demand placed on the receiver, which can lead to tighter design requirements.
The television broadcast bands are too wide in frequency to be covered by a single antenna, so the two options are separate antennas used for the VHF and UHF bands or a combination (combo) VHF/UHF antenna. [6] A VHF/UHF antenna combines two antennas feeding the same feedline mounted on the same support boom.
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 ...
This mast has two UHF antennas for receiving signals from different directions. The lower antenna is a bowtie array. The upper antenna is a Yagi design.. UHF television broadcasting is the use of ultra high frequency (UHF) radio for over-the-air transmission of television signals.
On 27 May 2011 the channel spacing on Australian UHF CB was changed, allowing the band to expand from 40 channels to 80 channels. [8] This was achieved by reducing the bandwidth of the existing channels and interleaving new channels between them, reducing channel spacing from 25kHz to 12.5kHz. The expansion effectively allows the use of 77 ...