What is a duplexer in a repeater?
A duplexer is a device that allows bi-directional communication over a single channel. In radio communications systems, it isolates the receiver from the transmitter while permitting them to share a common antenna. Most radio repeater systems include a duplexer.
What is a radio duplexer?
A duplexer is a three port filtering device which allows transmitters and receivers operating at different frequencies to share the same antenna. A duplexer typically consists of two band pass filters connected in parallel.
Can two ham radios use same antenna?
An element of filtering is required if you want to use two transmitters with one antenna. Diplexers allow either one radio to use two antennas, or two radios to share one antenna. The diplexers have filters that prevent transmitted RF energy from traveling into the second radio and causing damage.
What is the range of a radio repeater?
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.
What is RX and TX frequency?
Radio communication known as RT (Radio Telephony) uses a Tx (radio transmitter) to send out radio waves of a certain frequency and a Rx (radio receiver) to receive the radio waves at the same frequency. Radio waves consist of electro-magnetic energy in specific frequency bands within the radio frequency spectrum.
How many types of duplexer are there?
There are two predominant types of duplexer in use – “notch duplexers”, which exhibit sharp notches at the “unwanted” frequencies and only pass through a narrow band of wanted frequencies and “bandpass duplexers”, which have wide-pass frequency ranges and high out-of-band attenuation.
Can a CB antenna be used for ham radio?
A CB antenna can be used for ham radio by simply trimming the antenna down. As CB antennas are designed for frequencies around 27 MHz, the best one can do is trim the length in order to operate at or near ten meters in wavelength (about 28 MHz), 6 meters, or lengthen it to go to the 12 meters wavelength.
Can a ham radio operators use GMRS?
GMRS cannot transmit on ham frequencies legally and ham radio cannot transmit on GMRS frequencies legally.
Why RX frequency is higher than TX frequency?
The answer is simple too. It’s all about power considerations. In satcomm, the signals have to cross the atmosphere which presents a great deal of attenuation. The higher the frequency, the more is the signal loss and more power is needed for reliable transmission.