Towers & Such 2014

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    Andy Brown

    Every day sees humanity more victorious in the struggle with space and time.

    ~ Guglielmo Marconi

    GLOSSARY OF TERMS frequently used in this thread: (in U.S. unless otherwise noted)

    A or Grade A (dBu) = television broadcast field strength contour of 68, 71, and 74 (dBu) for channels 2-6, 7-13 and 14-69 respectively.

    AC = (1) Alternating current, the form in which electric power is delivered to businesses and residences. In alternating current (AC, also ac), the flow of electric charge periodically reverses direction. (2) In radio programming, a format known as Adult Contemporary

    AGC = Automatic Gain Control, a technique in electronic circuits whereby the output is used to adjust the gain of an amplifier.

    AM = (1) amplitude modulation, the oldest form of modulation whereby the amplitude of the transmitted signal is varied in relation to the amplitude of the information being sent (2) the standard broadcast band (530 to 1700 kHz in the U.S.)

    AMSL = the height of a tower or antenna above mean sea level

    amp = (1) amplifier (2) the fundamental measure of electrical current

    ATSC = ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks.

    B or Grade B (dBu) = television broadcast field strength contour of 47, 56, and 64 (dBu) for channels 2-6, 7-13 and 14-69 respectively.

    C = (1) the speed of light in a vacuum (2) Capacitance (the ability to store charge)

    Class = In radio and television broadcasting, how much power and coverage a licensee may implement is determined by Zone and Class. Zones (see below) are geographic. Zones determine what classes will be licensed within that zone.

    Classes for FM are:

    Classes for AM are:

    Classes for TV are:

    clear channel = a frequency on the AM band which provides the radio station with the highest protection from interference from other stations. A long story. It no longer means that only one transmitter operates on that channel

    Clear Channel = The company that ruined radio

    contour = a series of points at which the signal of a radio or television broadcast is at a referenced field strength. On flat land a non directional (omnidirectional) antenna will exhibit near circular contours, ideally. Contours are either “protected” contours or “interference contours.” In FM, the actual numerical values of these contours depends on Zone and Class. Also, when you are within 320 km of either Canada or Mexico, different spacing distances and contour values must be observed. Stations in Zone II that are not within 320 km of the Canadian border have their 60 dBu protected contour and three interfering contours, 40 dBu for co-channel, 54 dBu for 1st adjacent and 100 dBu for 2nd adjacent. protection.

    CP = (1) construction permit (2) circular polarization

    CPS = (see Hertz)

    CFR = Code of Federal Regulations Title 47: Telecommunications,

    the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. It is divided into 50 titles that represent broad areas subject to Federal regulation.

    (within title 47 the most discussed parts are normally Part 73 Radio Broadcast Services, but also may refer to Part 0, Part 1, Part 2, Part 15, Part 17, Part 74)

    CQUAM = Compatible Quadrature Amplitude Modulation, a system developed by Motorola for stereophonic broadcasting on mediumwave (AM)

    DA = (1) directional antenna,an antenna which radiates greater power in one or more directions or exhibits greater receive sensitivity in one or more directions (2) distribution amplifier, an amplifier that provides multiple outputs from one input

    DA-N = directional antenna at night

    DA-2 = directional antenna 24 hours, different patterns day and night

    DAB = digital audio broadcasting, the method for audio broadcasting digitally in many countries, principally in Europe.

    dB = decibel, a logarithmic unit used to express the ratio between two values of a physical quantity, often used to express the gain of an amplifier or the loss of signal strength as a signal propagates away from the antenna.

    DC = (1) direct current, the unidirectional flow of electricity (2) publisher of Batman, Superman and Justice League comic books

    DSSC = double sideband suppressed carrier, a form of modulation used in analog FM broadcasting

    DTV = digital television

    EMI = electromagnetic interference

    ERP = Effective Radiated Power, in FM radio and television broadcasting, the amount of power you are licensed to transmit, it is equal to transmitter power output (TPO) minus transmission line loss times the antenna gain.

    FM = (1) frequency modulation, the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. (Compare with amplitude modulation, in which the amplitude of the carrier wave varies, while the frequency remains constant.) (2) the FM broadcast band (88.1 to 107.9 in the U.S.)

    frequency = the number of occurrences of an electromagnetic field, usually referring to audio or radio signals, per unit time. Also see period and wavelength.

    Gm = transconductance, the ratio of the current change at the output port to the voltage change at the input port, usually in reference to a vacuum tube.

    HAAT = Height above average terrain, used in the prediction of coverage by television stations, FM radio stations and some wireless radio services, HAAT value is determined by taking 50 evenly spaced elevation points (above mean sea level [AMSL]) along at least 8 evenly spaced radials from the transmitter site (starting at 0 degrees [True North]). The 50 evenly spaced points are sampled in the segment between 3 to 16 km (formerly 2 to 10 miles) along each radial. The elevation points along each radial are averaged, then the radial averages are averaged to provide the final HAAT value. Terrain variations within 3 km (2 miles) of the transmitter site usually do not have a great impact on station coverage.

    For a full explanation click here and scroll down

    HAGL = height above ground level

    Hz = Hertz, the standard for measuring sinusoidal electricity. Previously known as CPS or cycles per second

    I = electrical current , the flow of charge (measured in amperes or amps)

    IF = intermediate frequency,

    IBOC = in band on channel, the current method for broadcasting audio digitally on the AM and FM bands

    IMD = intermodulation distortion

    Longley-Rice: An alternate method to the FCC method of predicting coverage that addresses the difficulty of determining exactly where a contour line falls when in fact the signal from a given transmitter may rise and fall above and below a given signal level numerous times along the path.

    LPFM = Low Power FM, a class of service in FM broadcasting

    LPTV = Low Power TV, a class of service in TV broadcasting

    NDA = non directional antenna

    NTSC = analog television engineering standards(National Television Services Committee)

    NFG = what happens to all vacuum tubes after a while

    P = Electrical Power, measured in watts, the product of current and voltage at the same point.

    PA = (1) power amplifier (2) public address

    PAL = Phase Alternating Line, an analog color video system developed in Germany that became common in many countries that formerly used monochrome systems with a 50 Hz refresh rate

    POL = polarization (also polarisation), in antenna theory the polarization is the orientation of the electric field, and is always 90º from the magnetic field

    Q = (1) in electrical and electronic circuits, the Q or quality factor is a dimensionless parameter that describes how under damped an oscillator is, characterizing its bandwidth relative to its center frequency, a high Q indicates a lower rate of energy loss (2) the head of R&D in the British Secret Service in the James Bond series (3) Captain Picard’s nemesis

    RF = radio frequency energy, signals that have a frequency greater than 20,000 Hz (20 kHz). Signals below that frequency are AF or audio frequency signals.

    RF Spectrum Ranges include:

    Very Low Frequency VLF 3 – 30 kHz

    Low Frequency LF 30 – 300 kHz

    Medium Frequency MF 300kHz – 3 MHz

    High Frequency HF 3 – 30 MHz

    Very High Frequency VHF 30 – 300 MHz

    Ultra High Frequency UHF 300 MHz – 3 GHz

    Super High Frequency SHF 3 GHz – 30 GHz

    Extremely High Frequency EHF 30 GHz – 300 GHz

    RFI = radio frequency interference

    RFR = radio frequency radiation,

    S/N = Signal to noise ratio of either the RF, visual or audio signal with reference to the associated noise floor.

    SECAM = Séquentiel couleur à mémoire, an analog color video system developed in France

    SOL = the prevailing attitude of employees when they learn Clear Channel has automated their station (see above)

    SSB = single side band, a form of modulation

    STL = studio-transmitter link, a system to deliver the program audio chain to the transmitter site from the studio

    T = Period, the inverse of frequency or the time for the electric wave to go through one full cycle.

    TPO = transmitter power output

    THD = total harmonic distortion

    translator = a low power class of service in FM broadcasting intended to repeat programming from an originating full power class station

    V = voltage, the electrical potential (difference) between two points

    VSB = vestigial sideband, a form of modulation (see NTSC)

    wavelength = in a sinusoidal wave, the distance over which the wave’s shape repeats





    XTAL = Crystal

    XMTR = Transmitter

    XFORMER = Transformer

    Z = impedance = the measure of the opposition that a circuit presents to a current when a voltage is applied (DC resistance plus AC resistance)

    Zones = In FM and TV broadcasting, for the purpose of allotments and assignments, the United States is divided into three zones

    FM Zones:

    TV Zones:

    λ = wavelength

    Ω = Resistance in Ohms

    π = pi, the ratio of a circle’s circumference to its diameter, and is approximately equal to 3.14159

    Ø = (1) the null set, (2) undefined (3) the sum and total of your political nemesis’s knowledge . . . depending on which side of this board it appears.

    60 dBu = 1 mv/M In FM broadcasting, the distance from the antenna where the propagated signal has attenuated to this value is considered in FM broadcasting as the limits of your Primary coverage or Protected contour. dBu references dB above 1 microvolt per meter (uV), that is to say 60dBu is 1,000 times the voltage at 0dBu ( 1 microvolt). In Zone I and I-A, Class B1’s primary protected contour is 57 dBu and for Class B’s it is 54 dBu. For all other stations in FM broadcasting, 60 dBu is the primary protected contour.

    Useful links:

    FM Query:

    AM Query:

    TV Query:

    The records returned in an above linked search will provide smart links to many of the other databases like ASR and CDBS. These queries may seem cluttered in what they give you, but are in reality a time saver once you get used to them.

    FCC Tools Homepage:

    Radio Tools:

    Longley Rice Coverage Prediction:

    ASR Antenna Search:

    ULS License access Search:

    CDBS public

    Daily Digest:

    Daily Digest previous issues:

    Electromagnetic Spectrum Chart:

    Radio Locator: Coverage maps (low resolution)

    Compiled from last year’s edition with corrections and suggestions made by posters.


    Very nice, Andy and thanks for restarting this thread! I would like to add a couple of things. The “HD” in “HD Radio” doesn’t stand for anything. The idea was for people to hear the term, think of HDTV and relate it to “quality”. It definitely does not stand for “hybrid digital”! Then there’s this: “RF = radio frequency energy, signals that have a frequency greater than 20,000 Hz (20 kHz). Signals below that frequency are AF or audio frequency signals.

    RF Spectrum Ranges include:

    Very Low Frequency VLF 3 – 30 kHz

    Low Frequency LF 30 – 300 kHz

    Medium Frequency MF 300kHz – 3 MHz

    High Frequency HF 3 – 30 MHz

    Very High Frequency VHF 30 – 300 MHz

    Ultra High Frequency UHF 300 MHz – 3 GHz

    Super High Frequency SHF 3 GHz – 30 GHz

    Extremely High Frequency EHF 30 GHz – 300 GHz” The way we learned the order of this table was by memorizing the following quote. “Very little men have very unusual sex experiences.”


    After last night(new years). This is too deep to read, LOL. Happy new years everybody. 8)


    There are VLF stations down to 11.904761 kHz.

    Andy Brown

    Cool article. Wild website


    Cool stuff! I guess I need to brush up on hyperbolic navigation… It is *not* obvious to me why frequencies such as 11.904761 kHz were chosen.

    I shall not delve into the details of hyperbolic navigation, but the reason for the mathematical relationship between the transmitter frequencies are bound up in the navigational purpose. The determination of the exact signal characteristics is an interesting mathematical puzzle. For the mathematical minded of you this is as easy as a piece of cake. There is another way to make out the exlusive Revda F4 frequency with another basenumber ! Can you find it ? The base harmonics that build up each signal are seen to be separated by 1 /( 3.6 sec ) or 0.27777….. Hz, but are not integer multiples of 0.27777…..Hz. Are there exceptions to this rule ? The operational RSDN-20 system frequencies are mathematical related to a base frequency of 744 1/21 Hz.

    Piece of cake? 😯

    Andy Brown

    Looks pretty deep, but I know a guy if we need help.

    I’m starting here:


    I calculated that the wavelength of 11.904761 kHz is 25.20000 km. It would seem that this particular distance or multiples of it would be significant (but why is this so?).

    Andy Brown
    Andy Brown

    The Commission has announced the following totals for broadcast stations licensed as of December 31, 2013:

    News Media Information 202 / 418-0500 Internet: TTY: 1-888-835-5322

    AM STATIONS 4727



    TOTAL 15,358





    TOTAL 1,784



    TOTAL 428




    TOTAL 10,100



    TOTAL 1,986

    LOW POWER FM 776



    Who is Colin Innes and why is he filing against almost every religious broadcaster in Oregon?

    For instance:

    KLVP Aloha OR FM BRH-20131017CDJ 250 C1

    N 45° 31′ 21.0″ W 122° 44′ 45.0″

    License 313 133 0.0 5.0

    Filed App for Renewal for FM Station;

    Licensee: Educational Media Foundation;

    Application Petition To Deny Renewal Of License.

    Petition To Deny Filed 01/02/2014 By Colin Innes;

    Applicant: Educational Media Foundation

    Andy Brown

    “Who is Colin Innes”

    Can’t find much about a person with that name living in Portland. Someone by that name is a business professor at UC Riverside, but so far unable to connect him to the complainant. The house at the address on the petition belongs to Nicolas Frisby according to

    “why is he filing against almost every religious broadcaster in Oregon?”

    Judging from this excerpt from the KLVP Petition to Deny (renewal of license) it is pretty simple and appears to be accurate.

    This Petition to Deny is being submitted to deny Educational Media Foundation’s (“EMF”) renewal of licenses that serve the Portland, Oregon metropolitan area on the grounds of (1) its neglect of coverage of any community issues, (2) its abuse of the main studio waiver rules, and (3) redundant and abused translator service.

    . . . There is a total of eight Portland-area channels carry programming from California with no local studio. The programming on EMF stations merely emulate commercial radio music programming stations with no public affairs coverage tackling any local issues of importance. The FCC states that radio stations must address “must air programming that is responsive to the needs and problems of its local community of license” and “…each station licensee must affirmatively identify those needs and problems and then specifically treat those local matters that it deems to be significant in the news, public affairs, political and other programming that it airs.”2 We assert eight metropolitan radio channels to rebroadcast two radio formats means there are four radio channels a piece broadcasting redundant music programming, delving into no local public affairs or political programming responsive to the needs and problems of its local community of licenses.

    This isn’t breaking news (the abuse of the rules by EMF and other national religious broadcasters is well known), but he is pointing out some discrepancies between the “rules” and practices of the F.C.C. I advise reading the whole document, it is not that long and shows the specifics of the extent to which these licensees are skirting the rules of main studio waivers, translators, and community service.


    I noticed today that K224DL 92.7 Portland has switched from K-Love to Air1. Apparently, Air1 is being delivered to the translator via KKCW-HD3. This gives Air1 much better metro coverage, since 92.7 recently upgraded to 99 watts. In fact, it’s my opinion that 92.7 has the best signal of all of the 99 watt translators on Skyline/Sylvan.

    I predict that Clear Channel trades the KKCW-HD3 channel for access to one of EMF’s other translators.


    Wow Andy, thank you for posting that info as it was a fascinating read!

    In other news, there was a “Petition to Deny” submitted for the renewal of KPOJ by Tom Dwyer. Unfortunately the text of the petition isn’t available…

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