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Show small, of unusual appearand, with out any towers such as mark the LF station, and is Situated about six miles south east of Delta town. Its broadcasting "radiator" is inside in-side a small house mounted above a circular steel frame or wheel, carried a counterpoise, about 36 ft in diameter, in horizontal position pos-ition , supported by a square steel framework 12 X 12 ft. , 15 wt. high This counterpoise "wheel"' is cov- r.iarked in miles exactly how far he is from a DME transmitter at an Omni-Range site. As to how it works, let's just say it is something some-thing like radar and let it go at that. ... Now, bear in mind that while the radio range signals of this station are radiated continuously and automatically, along with the DTA identification letters this station stat-ion also carries the regular wea- . i Urvm and functioned to carry Ori radio service ser-vice - - for airplanes and although because of Us pilot's error s the light plane shorted out the 44 000 volt lines in a shower of sparks, nobody was hurt. The write rwishes.to express thanks to Nathan E. Ward Chief Aircraft Communicator at Delta Radio for checking I this article and providing technical tech-nical data. er picture clarity is wanted, each type of television station will re- . quire even more frequencies!! Tele vision is a hog for spectrum space. The sector of UHF between 480 and 920 mc just been opened by the FCC for experimental television televis-ion use. The FCC charged with the duty of assigning various sectors of the spectrum to various uses, such as radio telephony, commercial broad cas television, radar, FM radio, Zf others. At this time studies (From the Delta Airport by J Dick Morrison) j DELTA RADIO . . One morning recently the pilot of a passing plane called Fairfield radio to learn the visibility at Fair ffed For some reason Fairfield did not receive the call, although it came in on a receiver at Delta S. This may have been due to some directional effect in the plane's radio set, or possibly to the fact that the plane was closer to Delta than to Fairfield. The communicator on duty at Delta heard the request repeated without a reply from Fairfield so he picked up a telephone and talk ed with the Fairfield communicator communicat-or over the CAA leased wire. Fair Held radio from Delta radio.. Stm-son Stm-son three zero four victor calling are under way to determine wnat space shall be alloted for televis- ! ion; how many frequencies can be alloted to each station what type of color television will prove best in actual use, etc. The probems involved in-volved are complex, and the decisions decis-ions made must affect whole industries in-dustries and the public interest for years to come. ered with heavy wire netting, and on top of it is the closed boxlike box-like structure 12 ft. square and perhaps 6 ft. high which encloses the radiators. The electronic equip ment is housed in a sectional steel building about 16 .by 28 ft. near the steel framework. This new VHF radiator operates on the frequency of 117.1 megacycles (mc). This new station is fully described des-cribed as a Very High Frequency Visual Omni - Directional Radio Range Station. Fortunately, we ther reports twice each nour, d m is used for two-way radio-tele-phone service with individual pilots. pil-ots. It is truly an electronic wonder. won-der. The new VOR radiator is one of 409 such stations planned by the CAA. As of last July 15, 294 of these had been placed in operat ion. This changeover from LI is part of a master plan to be completed com-pleted 10 or 12 years from now. Among other things, this ultimate program calls for such exacting i electronic controls that each pilot j SPECTRUM NOTES ... In connection with the foregoing forego-ing it may be appropriate here to explain a few points concerning radio spectrum. It is arbitrarily divided di-vided into four main sectors, the first being the low through high frequency bands, from 10 to 30,000 kilocycles (kc), a small part of which sector is used by the standard stand-ard broadcast stations Next is on three zero one five requesting visibility at Fairfield - - DJ . Fairfield radio immediately broad cast the requested information and the pilot received it from tair field radio, to which his set was tuned. The pilot of that particular plane thus receievd in the information inform-ation he wanted, without knowing that his call had been received at may abbreviate all these wuiua to the letters VOR, which is much easier to write and read. Visual means that with its use, and with proper receiving equipment, a pilot pil-ot may determine his course by means of dial indicators on the instrument panel of his plane, whereas the old LF system necessitated necess-itated that he listen to the range electronic i-uiii.. ,- j will be assigned a definite landing land-ing time at his destination even before he starts his flight, and will be advised to go faster or slower as he deviates from sched- " The physical plant of Delta radio consists of receiving and control equipment housed in the new Watchhouse Building at the airport air-port the towers and brick build- the very high Irequency ivut -tor of 30,000 kc (which equals 30 megacycles) to 300 megacycles. Above the VHF sector is the ulra high frequency (UHF) sector of 300 mc to 3000 mc, and beyond this, up to 30,000 mc is the super high frequency sector (SHi). a kilocycle equals 1000 cycles per second, and a megacycle equals . 1000 kilocycles, or one million cyc-i cyc-i Thus 30.000 mc e- Delta instead of Fal rf leld; tnai the Delta communicator had relayed relay-ed his request to Fairfield, and that Fairfield had broadcast the reply in response to a telehone call. All this took place as easiy and quick lv as an ordinary conversation a mong three people in the same , rVhiie most conversation between pilots and CAA communicators are - made directly between sender and signal. Omni-directionai mean, that the direction signals are equally equ-ally effective from every direction direct-ion where as the LF system indicated indi-cated only four points of the compass. com-pass. A further advantage is that the VHF frequency range is less subject to static and erratic behavior be-havior than the LF range. In flying the new VHF omnirange omni-range the pilot uses three basic instruments.The first in the Course ing of the LF station, and the radiator rad-iator structure and sectional steel building of the VHF station. Both broadcasters are controlled by the CAA communicators who work at the airport; no one is regularly m attendance at the stations, their operation being automatic except as it is directed by remote control. con-trol. , . . receiver, such proceedures as trie one described are not infrequent and are part of the service the CAA renders to fliers in the course of each day's work. In cases where direct communication is not established. estab-lished. Delta may come to the aid quals an incredible 30 billion vibrations vib-rations per second, yet high as this may seem, it is a low figure compared com-pared with light wave frequencies which run into the trillions. It is also of passing interest to note that television stations require re-quire wide frequency bands. At present, black and white tele-stations use bands six megacycles wide, or 6000 kilocycles wide. Since the whole standard radio broadcast broad-cast sector of the spectrum, m which all . commercial entertain -ment stations are included, uses only 107 bands in a total range of 1070 kilocycles it can be seen that one television station uses ; nearly six times as much sector l as all commercial standard stat-: stat-: ions together! When and if color c television comes, each color stat-t stat-t ion will need several times the sector space of a black and white s station, and furthermore, if great- Line Indicator. The vertical neeu-le neeu-le of this dial indicates that he is on course, or in which direction he deviates . When the needle moves right or left of center, his rule for correcting his course is to fly toward the needle. Both buildings are neaieu u. electricity, and cooled automatically automatic-ally as necessary to maintain a constant temperature best suited to the electronic equipment. Both are provided with standby power plants which start automatically in case of line power failure. In this connection, it is interesting interest-ing to recall the time, some years ago, when a small airplane approa ching for a landing at the airport alighted on the Telluride Powei lines and knocked out the curren' supply for the whole community while the automatic generator of Fairfield or Milford, and vice VeDelta has, in the past .notifield Ft Worth, Kansas City, San Diego and Los Angeles of aircraft calling call-ing them. It has even heard planes in Honolulu and Fairbanks calling their local towers. The main reason for this is that signals in the high frequency band may "skip . mat The second instrument is an wm-ni-Bearing Selector. This indicates the magnetic bearing of the aircraft air-craft either to or from the station. Still another remarkable development devel-opment made possible by the VOR svstem in Distance Measuring quipment. or DME. With this a pilot can tell by looking at a dial is, the signal may leave tne eir u, or begin skipping, about 40 miles from a transmitter and not reach the ground again for sometimes hundreds of miles. , The important thing is that any pilot be furnished the information he needs, and all concerned coop- erate in every way possible to render ren-der this service. He may want to know the wind direction and veloc ity at an airport where he intends to land, or he may want to know the condition of the landing field. During part of last winter, Delta airport was closed by snow, and such facts as this are always included in-cluded in the regular .broadcasts as well as given in response to individual inquiries. Such notices are also transmitted ,on teletype circuits to most CAA stitions west of the Mississippi, and broadcast by them. Delta radio is on the air constantly, con-stantly, 24 hours a day, but you can't hear it on most home radios because its frequencies are on sec- tors of the radio spectrum reserved for government services. All messages mes-sages originating at the CAA communications com-munications station at the airport are broadcast not by just one broad casting station, but by two. In addition ad-dition to broadcasting voice messages, mes-sages, both stations radiate range signals and call letters DTA serving serv-ing to identify Delta radio. The reason there are two broad-easting broad-easting stations is that the old low frequency (LF) range system is now obsolescent, and will in the course of time be superseded by the new system.. The new system sys-tem provides many advantages over ov-er the old. A large number of old LF aircraft radios are still in use, but as these wear out and are discarded all planes will be equipped equip-ped with sets in the very high frequency (VHF) range and the LF radiators will be put out of ser- vice. Most local people are ware of the existence of the old LF broadcaster, broad-caster, with its five 137 ft. towers and brick building, located about 2 miles southeast of Delta town. This LF range station uses the old A-N radio range system, with four directional beams, broadcasting broadcast-ing on a frequency of 212 kilo -cycles (kc.) This frequency is lower low-er than the standard broadcast band which uses the frequencies of 540 to 1600 kc. Comparatively few local people are aware of the existence of the new VHF radiator. (The word radiator rad-iator here has about the same meaning as broadcaster, or broadcasting broad-casting antenna, as used in commercial com-mercial radio terminology.) It is |