Ham Radio Uhf/vhf Repeaters. Olympism seeks to create a way of life based on the joy found in effort, the educational value of good example and respect for universal fundamental ethical principles. The two meter and 70 cm amateur radio bands are the most popular of all of the amateur radio bands and it is where the majority new hams start out. The seventy cm band is a UHF or Ultra High Frequency band and the two meter band is a VHF or Very High Frequency band. Upon obtaining an ham radio license or "ticket" most a ham radio operators first investment is in a dual-band hand held two way UHF/VHF radio, frequently referred to as an HT or Handy talkie, a name which evolved from the old phrase: walkie-talkie. Generally the ham radio operators second investment is in a mobile dual-band VHF/UHF transceiver or "rig" which they install in their vehicle or radio Shack. These two rigs have very similar functionality but the hand held battery-operated radio is generally limited to a maximum output power of about 5 watts. The mobile radio which is connected to the vehicles 12 Volt power supply, or if it used as a base station, to a transformer supplying 12 Volts DC and is capable of transmitting typically up to about 35 watts. VHF and UHF frequencies are line of sight. Depending on the power output and the location of the transmission antenna UHF and VHF signals are capable of reaching the visible horizon and maybe just a little beyond, but that is the limit. There is one notable exception to this rule which is Tropospheric ducting, where under very unusual and quite rare weather conditions VHF and UHF radio transmissions travel very much further than the horizon. amateur radio operators take advantage of this phenomena when it does occur by communicating with other hams over great distances. A five Watt Handy-talkie will have an effective range "based on the terrain and elevation" of just about 3 miles. A mobile radio on maximum power with a decent aerial in a good location will maybe have a maximum range of 15 to 20 miles under ideal conditions. To overcome this limitation in range amateur radio operators employ radio repeaters, which are frequently owned and operated by ham radio clubs, but some are privately owned. These repeaters are automatic transceivers that listen or receive on one frequency and transmit on a different frequency, this is usually referred to as "the split". The radio repeater takes the signal that it receives on the input frequency and instantaneously retransmits it on the output frequency using a lot more power frequently about one hundred Watts. In addition to the higher power most of these radio repeaters antennas are located on the top of very high towers or high buildings which actually increases the range. An amateur's HT can be used to transmit on the repeater's input frequency and receive on the repeater's output frequency effectively increasing the range of the hand held rig to just beyond the horizon maybe even as much as 30 or forty miles. Many radio repeater systems have several receiving antennas located throughout the repeater's coverage area but just one main transmitter. In this way a large city can be completely covered with a repeater system with hams being able to receive the radio repeater just about anywhere in the city and they are able to be received by the radio repeater or "hit the repeater" as it is generally referred to, again from almost anywhere in the city. In recent times some repeaters around the globe have been connected to the World wide web and may be linked to each other using the Web. For example an amateur radio operator in Bombay India with an Handy-talkie can chat, through their local repeater with a fellow ham who is driving in their car in New York city USA.
Some radio repeater systems are continually linked to each other but most are linked as and when required by the Ham and the link being disconnected at the end of the conversation or QSO as it is called by Ham radio operators. Generally ham repeaters are open to all licensed amateur radio operators at no cost. These repeaters do cost money to operate and maintain.They are generally funded by club membership dues and events held by the club like Hamfests. If an amateur finds themselves using a repeater frequently then maybe they should really contemplate joining the club that owns the radio repeater and help to sponsor it.
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