FM Repeater Basics
In amateur radio, one of the most common communication activities uses VHF or UHF FM repeaters. A repeater is simply an amateur radio station designed to receive signals on one frequency and retransmit them on another. Because they receive and transmit on different frequencies, they can do so simultaneously. A repeater is considered duplex operation since its receiver is separate from its transmitter.
A repeater is usually located in a good, high place where it can be easily heard by users over a wide area. The idea is to extend the range of hand-held and mobile transceivers that normally have limited, line-of-sight range.
To use a repeater, your transceiver operates in a split mode. You listen to the repeater's output frequency and transmit on its input frequency. Most modern transceivers will automatically adjust the different frequencies, called the offset. Some repeaters will also require a private line (PL) tone. This tone is used to filter out other radio transmissions on the same frequency in the area.
Most FM repeaters are open, meaning they are accessible to anyone who has the appropriate license privileges to use them. As long as you are courteous and well-mannered, you are welcome on most repeaters. However, some repeater systems are not open to everyone who wishes to use them. These are called closed repeaters, and they limit access to a particular group or activity.
The other communication activity, known as simplex operation, involves direct radio-to-radio communication. Ideally, repeaters should be used as a secondary means of communication if your equipment is not able to maintain direct contact with another station. The national simplex call frequencies are 146.52, 223.50, 446.0, 906.5, and 1294.5 MHz.
Club Owned Repeaters
The Vicksburg Amateur Radio Club owns and maintains two open repeaters, and anyone is welcome to use them. Our repeaters are Yaesu System Fusion capable and have emergency power. Both of these repeaters are located within the City of Vicksburg, Mississippi.
K5ZRO operates VHF on 147.270 MHz FM (+0.6 offset; PL 100 Hz), YSF, e-power
K5ZRO operates UHF on 444.850 MHz FM (+5 offset; PL 100 Hz), YSF, e-power
The club also maintains an APRS Digipeater, K5ZRO-1 operating on 144.390 MHz
Member Owned Repeaters
Additionally, the club has access to two open repeaters that are owned and maintained by VARC members.
W5WAF operates VHF on 145.410 MHz FM (-0.6 offset; PL 100), YSF, e-power and is located in Vicksburg, Mississippi.
AF5OQ operates VHF on 146.625 MHz FM (-0.6 offset; PL 141.3), YSF and is located in Port Gibson, Mississippi