His work, as important as it was in its own right, was a part of a continuum of progress in communications and electronics that since his time has brought forward color television, the personal computer, the Internet, cable and satellite radio and TV, personal mobile phones, audio, video and computing, digital stereo radio on both the medium wave and VHF-FM bands, and digital high definition television on VHF, UHF, cable and satellite.

Thereware 30 UHF and 7 VHF Port-au-Prince ( plus 5 cable TV systems )

Before cable-ready TV sets became common in the late 1980s, an electronic tuning device called a cable converter box was needed to receive the additional analog cable TV channels and transpose or convert the selected channel to analog radio frequency ( RF ) for viewing on a regular TV set on a single channel, usually VHF channel 3 or 4.

The GV-8 included a TV receiver for VHF and UHF channels.

Hence VHF networks are sometimes informally referred to by the channel number they are seen on terrestrial TV in the Mega Manila area ( e. g. Channel 2 or Dos for ABS-CBN, Channel 5 or Singko for TV5, and Channel 7 or Siyete for GMA Network ) while some networks have the channel numbers in their name ( e. g. TV5, Studio 23 and Net 25 which are seen on channels 23 and 25 respectively ).

All five requests were for each station to broadcast on channel 7 ; Frank Marx, ABC's vice president in charge of engineering, thought at the time that the low-band ( channels 2 through 6 ) TV channels would be reallocated for military use, thus making these five stations broadcasting on VHF channel 7 the lowest on the TV dial and therefore the best channel positions.

For analog TV, 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.

Several TV stations were allocated to VHF channels 3, 4 and 5A, which were within the FM radio bands although not yet used for that purpose.

In New Zealand, the four main Free-to-Air TV stations still use the VHF Television bands ( Band I and Band III ) to transmit to New Zealand households.

From then on, TV was broadcast on both VHF and UHF ( VHF being a monochromatic downconversion from 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.

* Red TV ( VHF signal 7 )

* UCV TV ( 9 VHF signal )

On playback, these devices often give the user the option to output the baseband signal or to modulate it onto a VHF or UHF frequency compatible with a TV tuner ( i. e., appearing on a selected TV channel ).

UHF TV signals are generally more degraded by moisture than lower bands, such as VHF TV signals.

VHF for TV transmission is slowly being phased out in Ireland – only RTÉ One and RTÉ Two are on VHF band III in some areas, and the more recently established stations ( TV3 and TG4 ) have only been broadcast on UHF.

The problem becomes even more severe on a cyclical basis when sunspot levels reach a maximum every 11 years and lower VHF band signals below 50 MHz can travel across the Atlantic Ocean or from coast to coast within North America on occasion.

For frequencies extending beyond the VHF band, cores made from non-conductive magnetic ceramic materials called ferrites are common.

* 10 nanoseconds ( 10 ns ) – cycle time for frequency 100 megahertz ( 1 Hertz ), radio wavelength 3 m ( VHF, FM band )

( Today, we refer to " ultra short waves " as the VHF band.

For wireless communications in the VHF and UHF frequency band ( the bands used by walkie-talkies, police, taxis and cellular phones ), one of the most commonly used methods is that of Okumura-Hata as refined by the COST 231 project.

* For signals in the UHF / VHF band propagating over the surface of the Earth the path loss increases with roughly 35 -- 40 dB per decade ( 10 -- 12 dB per octave ).

The most common usage of 2m band is mobile single or dual band VHF or VHF / UHF mobiles.

Also in part due to the typical output power of a VHF band is 50W, due to the FCC requirement of RF exposure evaluations needing to be conducted on power greater than 50W in the 2m band.

At the same time, a series of regulatory moves by the FCC opened up the more desirable VHF band for additional full power stations in sizable Eastern and Midwestern markets between 1958 and 1963, allowing ABC to acquire full-time affiliation agreements with additional full-coverage stations in key parts of the country.

Certain subparts of the VHF band have the same use around the world.

Other stations, including a variety of pay and regional free-to-air stations, are forced to broadcast in the UHF band, since the VHF band is very overloaded with four stations sharing a very small frequency band, which can be so overcrowded that one or more channels, more often than not one of the MediaWorks-owned channels ( TV3 and FOUR ), is unavailable in some smaller towns.

British television originally used VHF band I and band III.

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.

The general services in the VHF band are:

The first commercial networks in Australia involved commercial stations in Sydney, Melbourne, Brisbane, Adelaide, and later Perth, sharing programming, with each network forming networks based on their allocated channel numbers: TCN-9 Sydney, GTV-9 Melbourne, QTQ-9 Brisbane, NWS-9 Adelaide and STW-9 Perth together formed the Nine Network, while their equivalents on VHF channels 7 and 10 formed the Seven Network and Network Ten respectively.

* While Australia also uses PAL B on VHF, the frequency allocations of NZ differ somewhat from Australia.

ATN's Sydney transmissions-both DVB-T terrestrial digital and analog PAL-are on VHF RF Channels 6 and 7 respectively and are broadcast from masts operated by Transmitters Australia ( TXA ) at Artarmon and / or Willoughby.

The other common output frequency set in Australia was Channel 0 and 1 on the VHF band throughout the 1980s.

In 1942, a pioneering VHF frequency-modulated radio-link was established between Creg-na-Baa and the UK to provide an alternative to the sub-sea cable.

Hull's magnetron was not originally intended to generate VHF ( very-high-frequency ) electromagnetic waves.

The Space Fence is intended to replace the Air Force Space Surveillance System, or VHF Fence, that was transferred from the Navy to the Air Force in 2004.

A few years earlier, the federal regulator had placed a five-station cap on all television networks: no network was allowed to own more than five VHF television stations.

" The Amateur Radioteletype and VHF Society " was founded in 1946 in Woodside, NY.

Before the All-Channel Receiver Act of 1962 required US television receivers to be able to tune the entire VHF and UHF range ( which in North America was NTSC-M channels 2 through 83 on 54 to 890 MHz ), a set-top box known as a UHF converter would be installed at the receiver to shift a portion of the UHF-TV spectrum onto low-VHF channels for viewing.

Television on VHF 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 60s ).

It is considered that one of the most significant events in the history of broadcast television regulation was the creation of an artificial scarcity of VHF licenses.

Television was added to the VHF band in 1941 on channels one through six.

From 1992 to 1995, the goal was to produce a radio for the U. S. Army which could operate from 2 MHz to 2 GHz, and operate with ground force radios ( frequency-agile VHF, FM, and SINCGARS ), Air Force radios ( VHF AM ), Naval Radios ( VHF AM and HF SSB teleprinters ) and satellites ( microwave QAM ).

Because many people were already using 40-channel radios prior to legalization, the American band plan ( with AM and SSB ) was adopted ; a VHF band was added in 1994.

In a short period of time, Venevisión greatly expanded nationally, and was seen in most of Venezuela on many VHF and UHF channels.

Designed in 1937 at the Bureau of Air Commerce's research center, this system operated in the VHF band around 63 mHz and was an incremental improvement over prior aviation navigation systems such as the four-course radio range.

At the time, SBS was broadcasting on UHF Channel 28 and VHF Channel 0, with a planned discontinuation of the latter at some time in the future.

The idea that the VHF band could be allowed to " die " was no longer practical.

In his system the output of the three camera tubes were re-combined to produce a single " luminance " value that was very similar to a monochrome signal and could be broadcast on the existing VHF frequencies.