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54-589: The mountain has a north summit (613.2 m) and a south summit (606.0 m); on the latter is the Ludwig observation tower . The Blättersberg lies in the Haardt , the eastern mountain chain of the Palatine Forest, in the eponymous nature park . Its summit rises 3 kilometres west-northwest of Rhodt unter Rietburg , within whose territory most of the mountain lies, 4.5 km west-southwest of Edenkoben , between

108-509: A flag pole at its top. Some of these towers are permanently accessible, either free or with the payment of an admission fee. Others are accessible only at certain times, in most cases only with the payment of an admission fee. At these towers the platform is usually open, with some having a restaurant in the basement. There are also towers with a much more extensive use; for example. the observation tower on Rossberg mountains in Reutlingen contains

162-460: A hotel within its structure. Although most of these towers were initially built before World War I , such structures are still being built, in particular as attractions at horticultural shows . Modern observation towers are in most cases no longer built of brick, but concrete, steel and wood are used as the preferred building materials. Permanent observation towers are also sometimes found in amusement parks , however in parks where each attraction

216-515: A lighthouse is usually between 10 and 50 metres high, and is almost always open air. Some sports facilities have high buildings with observation decks. This is often the case at ski jumps, as these have a tower and are usually unused in the summer. In addition, there are other sports facilities with observation decks, like the inclined tower of the Montreal Olympic stadium. Access to the platform of nearly all sports facilities with observation deck

270-499: A process to move these stations to UHF bands to free up valuable VHF spectrum for its original purpose of FM radio. In addition, by 1985 the federal government decided new TV stations are to be broadcast on the UHF band. Two new VHF channels, 9A and 12, have since been made available and are being used primarily for digital services (e.g. ABC in capital cities) but also for some new analogue services in regional areas. Because channel 9A

324-666: A proposed transmitter station. VHF is the first band at which wavelengths are small enough that efficient transmitting antennas are short enough to mount on vehicles and handheld devices, a quarter wave whip antenna at VHF frequencies is 25 cm to 2.5 meter (10 inches to 8 feet) long. So the VHF and UHF wavelengths are used for two-way radios in vehicles, aircraft, and handheld transceivers and walkie-talkies . Portable radios usually use whips or rubber ducky antennas , while base stations usually use larger fiberglass whips or collinear arrays of vertical dipoles. For directional antennas,

378-402: A restaurant. The height of these platforms, which can be glassed or open-air depending on the height of the building, where they are most common on the topmost floor. As a rule access usually requires the payment of an admission fee, is possible by elevator only at dedicated opening times. Also numerous water towers have, a usually open-air observation deck opened for public traffic, whose height

432-505: A result, FM radio receivers such as those found in automobiles which are designed to tune into this frequency range could receive the audio for analog-mode programming on the local TV channel 6 while in North America. The practice largely ended with the DTV transition in 2009, although some still exist. The FM broadcast channel at 87.9 MHz is normally off-limits for FM audio broadcasting; it

486-428: A rule an elevator is available in these buildings for the visitors of the observation deck, as the observation deck lies usually very highly (mostly within the range between 50 and 200 metres, at some towers also more highly). Many of these towers have also a tower restaurant, which can be designed as revolving restaurant. While tower restaurants for the protection of the restaurant guests from the wind are in closed rooms,

540-609: A rule, since these buildings are mostly not higher than 20 metres. Active watch towers are not as a rule accessible to the public, since they usually serve for the monitoring of sensitive ranges. However watch towers can be quite ordered for forest fire monitoring a platform accessible for the public or be used during times without forest fire risk as observation towers. Shut down watch towers can however be easily converted to observation towers. Also some radio towers were so built that they can be used apart from their function as transmitting tower also as observation tower. A condition for this

594-433: A t-antenna for medium wave and stands on insulators. However one notices at the first experimental transmissions that at the tower voltages would arise, which would have unpleasant consequences for visitors and so the tower was grounded by the elevator shaft. However this shifted direction of main beam of transmitter away from actual supply area, the city of Berlin. As before World War II nearly whole radio traffic took place in

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648-409: A tower restaurant and allow visitors access via elevators. Also common is the usage of water towers as observation towers. As in the case of TV towers the visitor will usually reach the observation deck by elevator, which is usually at a lower height above ground The typical height of the observation deck of water towers is 20 metres up to 50 metres, while the typical height of the platform of TV towers

702-524: Is a radio band which, in most of the world, is used for FM broadcasting . In North America , however, this bandwidth is allocated to VHF television channel 6 (82–88 MHz). The analog audio for TV channel 6 is broadcast at 87.75 MHz (adjustable down to 87.74). Several stations, known as Frankenstations , most notably those joining the Pulse 87 franchise, have operated on this frequency as radio stations, though they use television licenses. As

756-669: Is a sufficiently stable construction, which permits a permanent safe visitor entrance without interruption of the transmission services. This is the case for towers for radio services in the UHF/VHF-range the case, not however for most types of radio towers for long and medium wave, why a use of these structures as observation tower is impossible in most cases. That the use of a tower as radio tower for medium wave and observation tower not well fits, showed up in Radio Tower Berlin , which originally carried together with an 80 metres high mast

810-448: Is from 80 metres up to 200 metres. Finally, some church towers may have observation decks, albeit often without an elevator. Many other buildings may have towers which allow for observation. In particular prior to World War I rambler associations, and some municipalities, built observation towers on numerous summits. Usually these towers were built of stone, however sometimes wood or iron was also used. At nearly all these towers access to

864-436: Is in contrast to the entrance of the church usually only possible under payment an admission fee at the opening times of the church. The height of the observation decks is usually in the range between 20 and 50 metres. The platform is nearly always open-air. Some lighthouses have an observation deck open to the public. Access is usually by stairs. An admission fee is often charged and hours may be limited. The observation deck of

918-558: Is less of a problem in this and higher frequency bands than at lower frequencies. The VHF band is the first band at which efficient transmitting antennas are small enough that they can be mounted on vehicles and portable devices, so the band is used for two-way land mobile radio systems , such as walkie-talkies , and two way radio communication with aircraft ( Airband ) and ships ( marine radio ). Occasionally, when conditions are right, VHF waves can travel long distances by tropospheric ducting due to refraction by temperature gradients in

972-486: Is mostly as the height of older observation towers in the height range between 10 and 50 metres. It can be reached depending upon tower by stairs or by an elevator. Some water towers have also a tower restaurant. Prospect platforms of water towers are nearly only accessible under payment during the opening times, which are different for each tower. Also some church towers possess observation decks. However elevators are only available in rare cases. The entrance of this platform

1026-427: Is not separately paid for, panorama rides are preferred. Watch towers are observation towers, on which persons supervise a larger area. Strictly speaking, control towers also fall into this category, although surveillance from these structures is mostly done in a non-optical way using Radar . Watch towers usually have a closed pulpit to protect the observer against bad weather. Watch towers do not have an elevator as

1080-463: Is not used for television services in or near Sydney, Melbourne, Brisbane, Adelaide or Perth, digital radio in those cities are broadcast on DAB frequencies blocks 9A, 9B and 9C. VHF radio is also used for marine Radio as per its long-distance reachability comparing UHF frequencies. Example allocation of VHF–UHF frequencies: Until 2013, the four main free-to-air TV stations in New Zealand used

1134-551: Is only possible during opening times after paying an admission fee. Depending upon the building the access can be done by an elevator and/or a stairway. The platforms can be vitreous or open. The height above ground lies usually between 10 and 50 metres. Fire lookout towers have been used widely in Australia, Canada, and the United States to hoist fire lookout persons to heights where they can identify and report new wildfires. In

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1188-536: Is reserved for displaced class D stations which have no other frequencies in the normal 88.1–107.9 MHz subband to move to. So far, only two stations have qualified to operate on 87.9 MHz: 10–watt KSFH in Mountain View, California and 34–watt translator K200AA in Sun Valley, Nevada . In some countries, particularly the United States and Canada, limited low-power license-free operation

1242-735: The HF band there is only some reflection at lower frequencies from the ionosphere ( skywave propagation). They do not follow the contour of the Earth as ground waves and so are blocked by hills and mountains, although because they are weakly refracted (bent) by the atmosphere they can travel somewhat beyond the visual horizon out to about 160 km (100 miles). They can penetrate building walls and be received indoors, although in urban areas reflections from buildings cause multipath propagation , which can interfere with television reception. Atmospheric radio noise and interference ( RFI ) from electrical equipment

1296-877: The Henninger Turm , a grain silo with tower restaurant and observation deck in Frankfurt, the bell tower of Berlin Olympic stadium , whose platform is accessible by an elevator, the winding tower of the mining industry museum in Bochum, which has an open-air observation deck to which an elevator runs or a wind turbine in Holtriem wind park, which is equipped with a closed platform accessible over stairs. Also aerial tramway support towers, which serve as observation tower (and aerial tramway station), were realized, like Torre Jaume I in Barcelona. Even on

1350-764: The Ludwig Tower ( Ludwigsturm ). From the viewing platform of the 15 metre-high tower the view to the east into the Rhine Plain is blocked by the trees, but elsewhere one can see as far as the Badener Höhe and Hornisgrinde in the Black Forest to the south-southeast, nearby Trifels Castle to the southwest, the Frankenweide forest with its hills, the Weißenberg ( Luitpold Tower ) and Hortenkopf (transmission mast) to

1404-611: The Yagi antenna is the most widely used as a high gain or "beam" antenna. For television reception, the Yagi is used, as well as the log-periodic antenna due to its wider bandwidth. Helical and turnstile antennas are used for satellite communication since they employ circular polarization . For even higher gain, multiple Yagis or helicals can be mounted together to make array antennas . Vertical collinear arrays of dipoles can be used to make high gain omnidirectional antennas , in which more of

1458-605: The observation deck , usually at a height of between 5 and 40 metres, is only possible by way of stairs. Most of these towers are used only for tourism, however some of these towers might also be used, at times of high forest fire risk, as fire observation posts or in times of war as military observation posts with anti-aircraft positions placed beside it. Further uses were not intended at most of these buildings, although some of these towers today now carry antennas for police/fire engine radios, portable radio or low power FM- and TV-transmitters. Older observation towers frequently have

1512-435: The 10 VHF channels were insufficient to support the growth of television services. This was rectified by the addition of three additional frequencies-channels 0, 5A and 11. Older television sets using rotary dial tuners required adjustment to receive these new channels. Most TVs of that era were not equipped to receive these broadcasts, and so were modified at the owners' expense to be able to tune into these bands; otherwise

1566-538: The 625-line colour signal), with the exception of BBC2 (which had always broadcast solely on UHF). The last British VHF TV transmitters closed down on January 3, 1985. VHF band III is now used in the UK for digital audio broadcasting , and VHF band II is used for FM radio , as it is in most of the world. Unusually, the UK has an amateur radio allocation at 4 metres , 70–70.5 MHz. Frequency assignments between US and Canadian users are closely coordinated since much of

1620-453: The Americas and many other parts of the world, VHF Band I was used for the transmission of analog television . As part of the worldwide transition to digital terrestrial television most countries require broadcasters to air television in the VHF range using digital, rather than analog encoding. Radio waves in the VHF band propagate mainly by line-of-sight and ground-bounce paths; unlike in

1674-549: The Canadian population is within VHF radio range of the US border. Certain discrete frequencies are reserved for radio astronomy . The general services in the VHF band are: Cable television , though not transmitted aerially, uses a spectrum of frequencies overlapping VHF. The U.S. FCC allocated television broadcasting to a channelized roster as early as 1938 with 19 channels. That changed three more times: in 1940 when Channel 19

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1728-516: The Edenkoben valley in the north and the Modenbach valley in the south, and 1.6 km (all as the crow flies ) northwest of the village of Weyher in der Pfalz . The mountain can be clearly made out from the Rhine Plain. On its east-northeastern flank, to the west and above the stately home of Villa Ludwigshöhe that is visible for miles, is the castle of Rietburg (Rhodt), which is also a landmark. At

1782-417: The United States, there once were over 5,000 fire lookout towers. Areas where birdlife congregates are often associated with bird observation towers to assist with viewing. Hyperboloid structures have a hyperboloid shape that is usually lattice framework and an observation deck on top. There are also some very different observation towers, which don't fit into other categories. Examples for this are

1836-468: The VHF television bands ( Band I and Band III ) to transmit to New Zealand households. Other stations, including a variety of pay and regional free-to-air stations, were forced to broadcast in the UHF band, since the VHF band had been very overloaded with four stations sharing a very small frequency band, which was so overcrowded that one or more channels would not be available in some smaller towns. However, at

1890-780: The ancient world, as long ago as the Babylonian Empire. Observation towers that are used as guard posts or observation posts over an extended period to overlook an area are commonly called watchtowers instead. Similar instances of observation towers are recognised as crow's nests , observatories , viewing platforms , etc. Observation towers are an easily visible sight on the countryside, as they must rise over trees and other obstacles to ensure clear vision. Older control rooms have often been likened to medieval chambers. The heavy use of stone, iron, and wood in their construction helps to create this illusion. Modern towers frequently have observation decks or terraces with restaurants or on

1944-403: The antenna's power is radiated in horizontal directions. Television and FM broadcasting stations use collinear arrays of specialized dipole antennas such as batwing antennas . Certain subparts of the VHF band have the same use around the world. Some national uses are detailed below. The VHF TV band in Australia was originally allocated channels 1 to 10-with channels 2, 7 and 9 assigned for

1998-427: The atmosphere. VHF transmission range is a function of transmitter power, receiver sensitivity, and distance to the horizon, since VHF signals propagate under normal conditions as a near line-of-sight phenomenon. The distance to the radio horizon is slightly extended over the geometric line of sight to the horizon, as radio waves are weakly bent back toward the Earth by the atmosphere. An approximation to calculate

2052-671: The desire existed to provide these towers with a tower restaurant and an observation deck, in order to make the building of towers more economical via admission fees and increased notability. Several water towers were also built with this in mind, but many have not survived to the modern day. Very high frequency Very high frequency ( VHF ) is the ITU designation for the range of radio frequency electromagnetic waves ( radio waves ) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and

2106-533: The elevator in the late 19th century made taller observation decks possible. Most notably, the Eiffel Tower and the Blackpool Tower were built in this era. Radio towers developed as combined sending and observation tower between 1924 and 1926 in the city of Berlin . After World War II , a great need for tall observation towers arose, due to their dual usage as television and radio transmitters. In large cities,

2160-468: The end of 2013 , all television channels stopped broadcasting on the VHF bands, as New Zealand moved to digital television broadcasting, requiring all stations to either broadcast on UHF or satellite (where UHF was unavailable) utilising the Freeview service. Refer to Australasian television frequencies for more information. British television originally used VHF band I and band III . Television on VHF

2214-552: The initial services in Sydney and Melbourne , and later the same channels were assigned in Brisbane , Adelaide and Perth . Other capital cities and regional areas used a combination of these and other frequencies as available. The initial commercial services in Hobart and Darwin were respectively allocated channels 6 and 8 rather than 7 or 9. By the early 1960s it became apparent that

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2268-408: The line-of-sight horizon distance (on Earth) is: These approximations are only valid for antennas at heights that are small compared to the radius of the Earth. They may not necessarily be accurate in mountainous areas, since the landscape may not be transparent enough for radio waves. In engineered communications systems, more complex calculations are required to assess the probable coverage area of

2322-431: The local countryside. Observation tower An observation tower is a structure used to view events from a long distance and to create a full 360 degree range of vision to conduct long distance observations . Observation towers are usually at least 20 metres (66 ft) tall and are made from stone, iron, and wood. Many modern towers are also used as TV towers, restaurants, or churches. The towers first appeared in

2376-464: The long -, medium and shortwave range, first after World War II with introduction of radio services in UHF/VHF-range required towers only acting as antenna carriers, radio towers with observation decks built. For this the closed reinforced concrete construction way was nearly always used. Radio towers with observation decks often serve for TV transmission or for radio relay link services and are called therefore usually TV tower or telecommunication tower. As

2430-826: The next higher frequencies are known as ultra high frequency (UHF). VHF radio waves propagate mainly by line-of-sight , so they are blocked by hills and mountains, although due to refraction they can travel somewhat beyond the visual horizon out to about 160 km (100 miles). Common uses for radio waves in the VHF band are Digital Audio Broadcasting (DAB) and FM radio broadcasting, television broadcasting , two-way land mobile radio systems (emergency, business, private use and military), long range data communication up to several tens of kilometers with radio modems , amateur radio , and marine communications . Air traffic control communications and air navigation systems (e.g. VOR and ILS ) work at distances of 100 kilometres (62 miles) or more to aircraft at cruising altitude. In

2484-558: The owner had to buy a new TV. Several TV stations were allocated to VHF channels 3, 4 and 5, which were within the FM radio bands although not yet used for that purpose. A couple of notable examples were NBN-3 Newcastle , WIN-4 Wollongong and ABC Newcastle on channel 5. While some Channel 5 stations were moved to 5A in the 1970s and 80s, beginning in the 1990s, the Australian Broadcasting Authority began

2538-417: The prospect platform can be open or in a closed room. An open platform is more favourable for photographing, since no reflexes at the disk arise, while closed platforms are for many visitors more pleasant. Prospect outlooks on TV towers are opened only at certain times and their entrance is possible only under payment of an admission fee. Also numerous highrise buildings have observation decks , sometimes even

2592-505: The pylons of suspension bridges were already observation decks installed, as the example of Nový Most in Bratislava shows. A very unusual observation tower is Pont basculant de la Seyne-sur-Mer . It was once a bascule bridge, now permanently put upright and used as observation tower. In Germany, observation towers first appeared on the countryside at the end of the 18th century. These early towers were often built by wealthy aristocrats . It

2646-454: The roof of mountain stations of an aerial ropeway. Frequently observation towers are used also as location of radio services within the UHF / VHF range ( FM sound broadcasting , TV, public rural broadcasting service, and portable radio service). In some cases this usage of the tower is at least as important as its use as an observation tower. Such towers are usually called TV towers or telecommunication towers. Many towers are also equipped with

2700-647: The southern foot of the mountain, by the upper reaches of the Modenbach stream, lies the historic estate of the Buschmühle mill. The elevation of the Blättersberg is given on some topographic maps as 613.2 m, but on others as 618 m. About 60 metres south-southeast of the summit is another high point, 611.8 m. On the southern summit of the Blätterberg stands an observation tower , built in 1883, called

2754-669: The west, the nearby Kesselberg mountain to the northwest and the highest point in the Palatine Forest, the Kalmit , to the north-northeast. The Blättersberg and the Ludwig Tower may be reached from the top station of the chair lift near Villa Ludwigshöhe (530.8 m) or from the Hüttenbrunnen hiker's car park in the Edenkobener valley above the Kohlplatz . Numerous hiking trails run through

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2808-406: Was deleted and several channels changed frequencies, then in 1946 with television going from 18 channels to 13 channels, again with different frequencies, and finally in 1948 with the removal of Channel 1 (analog channels 2–13 remain as they were, even on cable television ). Channels 14–19 later appeared on the UHF band, while channel 1 remains unused. 87.5–87.9 MHz

2862-399: Was in black and white with 405-line format (although there were experiments with all three colour systems- NTSC , PAL , and SECAM -adapted for the 405-line system in the late 1950s and early 1960s). British colour television was broadcast on UHF (channels 21–69), beginning in the late 1960s. From then on, TV was broadcast on both VHF and UHF (VHF being a monochromatic downconversion from

2916-510: Was not until the mid-19th century that citizens took control of the construction of such towers. In Austria and Switzerland many observation towers were established by alpine and tourist associations, and continue to be cared for by them. In the Waldigen Mountains , many citizen committees were active. Because of the long reign of emperor Franz Joseph , many observation decks carry the name "anniversary observation platform". The invention of

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