CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html - NTP

This is a discussion on CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html - NTP ; NRC Short Wave Station Broadcasts (CHU) http://inms-ienm.nrc-cnrc.gc.ca/time...adcasts_e.html NOTICE: About the New Messages on CHU - October, 2006 The added messages on CHU are: "On April 1, 2007, CHU needs to stop operating, change frequencies, or re-licence. Contact radio.chu@nrc.gc.ca or mail ...

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Thread: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html

  1. CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html


    NRC Short Wave Station Broadcasts (CHU)
    http://inms-ienm.nrc-cnrc.gc.ca/time...adcasts_e.html

    NOTICE:
    About the New Messages on CHU - October, 2006

    The added messages on CHU are:

    "On April 1, 2007, CHU needs to stop operating, change frequencies, or
    re-licence. Contact radio.chu@nrc.gc.ca or mail CHU Canada K1A 0R6," and

    « En avril 2007, CHU doit soit cesser ses opérations, soit changer de
    fréquence, soit renouveler sa licence. Contactez radio.chu@cnrc.gc.ca ou
    écrivez à CHU Canada, Conseil national de recherches, K1A 0R6. »

    This outreach is to collect information from users of CHU to help shape
    recommendations concerning what should be done concerning changes to CHU
    that will have to be in place by April 2007.

    In April 2007 the licence on 7.335 MHz will have to be modified to reflect
    changes on the status of the band allocation by the International
    Telecommunications Union. This frequency has been changed from "fixed
    service" to "broadcast". (The ITU decision does not affect the frequencies
    3.33 MHz and 14.67 MHz.)

    Some alternatives are:

    Re-licencing just might be possible, calling the 7.335 MHz a "broadcast".

    It is also possible to stop using that frequency (the most useful of the
    three we use). Stopping one signal is the easiest solution but could create
    problems for some clients who are counting on this particular signal.

    Change the frequency from 7.335 MHz to a nearby fixed-service frequency. It
    would need some investment from our part in new hardware and in manpower. It
    could also create problems for clients, and likely not all radios will be
    able to tune to the new frequency.

    Closure of the entire CHU operation, as discussed below.

    To be seriously considered, any of the above alternatives will need to have
    a zero-based budgeting justification prepared, comparing it against the
    least expensive alternative of closing CHU entirely. CHU is entering a phase
    where major investment in new transmitters will be required if it is to be
    kept operating. In the absence of input from the CHU user community,
    concerning the importance of CHU's contribution in the modern world, this
    last option is an inescapable recommendation.

    The CHU code is also used as a radio clock, which can be used as a reference
    clock for an NTP time server. Software drivers have been written that can
    obtain the date and time from the code and that tune a digitally tuned radio
    to one of our 3 frequencies, to get the best signal. Users of this service
    generally don't listen to the audio broadcast. So we cannot gauge the usage
    by sending this announcement.

    Please, if you know of anyone using CHU but not aware of the possible
    changes to its frequency usage, let them know and ask them to contact us
    about any essential uses. Also if you have an important use for CHU signals,
    please tell us how you use our signals.

    We are preparing the case to keep CHU in operation.

    CHU Time Service

    Time accuracy superior to telephone time accuracy is available throughout
    Canada and in many other parts of the world by means of NRC's radio time
    signals broadcast continuously from short wave radio station CHU. If
    corrections are made for the propagation delay from CHU to the user, and for
    delays in the user's receiver, an accuracy of better than 1 ms can be
    obtained. Signal availability at a user's location depends on ionospheric
    conditions. CHU also broadcasts a time code which can be decoded with common
    computers and modems.

    Three frequencies are used: 3330, 7335, and 14 670 kHz. The transmission
    mode, upper single sideband with carrier re-inserted, provides time signal
    service without requiring a special SSB radio, and also provides three
    standard frequencies. The frequencies are derived from one of a trio of
    closely synchronized atomic clocks located at the transmitter site. Three
    clocks are employed to permit majority logic checking. CHU time signals are
    also derived from these clocks. The clocks at the CHU transmitter site,
    about 20 km from NRC's time laboratory, are compared daily with the NRC
    primary cesium clocks.

    Normally CHU's emission times are accurate to 10-4 s, with carrier frequency
    accuracy of 5x10-12, compared to NRC's primary clocks, which are usually
    within 10 microseconds and 1x10-13 compared to UTC. UTC is the international
    official time reference. It is constructed by the Bureau International des
    Poids et Mesures (BIPM), based on the average of laboratory and commercial
    atomic clocks located in laboratories around the world. It is steered in
    frequency using the primary cesium standards (such as those at NRC) located
    at some of the major time laboratories. UTC loosely follows the
    irregularities of the astronomical time scale UT1, which is needed in
    astronomical observations and in celestial navigation. Since 1972, leap
    seconds have been used to keep UTC within 0.9 s of UT1. The difference [UT1-
    UTC] is called DUT1, and this fraction of a second [-0.8 s to +0.8 s] is
    broadcast by means of an internationally accepted code. To decode the size
    of DUT1, in tenths of a second, a user counts the number of emphasized
    seconds markers in one minute. For CHU, the emphasized seconds pulses are
    split, so that a double tone is heard. When the emphasis is on seconds 1
    through 8, DUT1 is positive; and when DUT1 is negative, seconds 9 through 16
    are used.

    The first minute of each hour commences with a full 1 s pulse of 1000 Hz
    tone, followed by 9 s of silence, and then the normal pattern of 0.3 s
    pulses of 1000 Hz at one-second intervals. The normal pattern for each of
    the next 59 minutes starts with a 0.5 s 1000 Hz pulse, followed by the DUT1
    code employing split 0.3 s pulses where required, and normal 0.3 s pulses up
    to and including that at 28 seconds. The pulse at 29 seconds is omitted.
    Following the normal pulse at 30 seconds, for a 9 s period, 1000 Hz pulses
    of 0.01 s occur, each followed by the CHU FSK digital time code described in
    CHU Broadcast Codes. The pulses between 40 and 50 seconds are of normal
    length. In the final 10 s period of each minute a bilingual station
    identification and time announcement is made, with the 1000 Hz seconds
    pulses shortened to "ticks". Each minute's announced time refers to the
    beginning of the pulse which follows. Since April 1, 1990, the announced
    time is always UTC.

    The CHU station is located 15 km southwest of Ottawa at 45º 17' 47" N, 75º
    45' 22" W. Main transmitter powers are 3 kW at 3330 and 14 670 kHz, and 10
    kW at 7335 kHz. Individual vertical antennas are used for each frequency.
    The electronics systems feeding the transmitters are duplicated for
    reliability, and have both battery and generator protection. The generator
    can also supply the transmitters. The announcements are made by a talking
    clock using digitally recorded voices.
    Historical Information

    Radio station CHU is operated by the Institute for National Measurement
    Standards at the National Research Council of Canada.

    The call letters CHU were first used for Canadian time transmission in 1938,
    on the modern frequencies, 3330 KHz, 7335 KHz and 14670 KHz. Before that the
    call letters of essentially the same transmissions were VE9OB. The carrier
    frequency has been the specified standard since 1934; before that the quartz
    oscillators had been tuned to standard wavelengths. Continuous transmissions
    at a wavelength of 20.4 m had started in 1933, joining the 40.8 m and 90 m
    transmissions, which began in 1929 (daytime only).

    Daily transmission on a wavelength of 52.5 m had begun in 1928 under the
    call letters 9CC (later VE9CC), but ceased with the startup of 40.8 m
    operation. 9CC had started experimental time transmission in 1923 on 275 m,
    and license 3AF had operated in 1922. Thus there is quite a range of
    possible dates to assign to the establishment of CHU; we lean towards 1929
    as being the start of daily time transmissions at essentially the modern
    frequencies. Of course there has been quite a change in equipment and
    accuracy over the years, but the largest improvement was with the change to
    cesium atomic clocks in 1967. In 1970 the responsibility of operating CHU
    was transferred from the astronomers at the Dominion Observatory, to the
    physicists at the National Research Council.

    Since 1970, the National Research Council has been charged with maintaining
    official time for Canada. The short wave radio station CHU is one, but only
    one of the ways that official time is disseminated across Canada.

    Following internationally accepted recommendations, Canada and other
    countries have official time scales in agreement within 10µs. Since CHU's
    transmissions are well within 100µs of official Canadian time, for all
    distant users of CHU, the dominant source of time error comes from the radio
    wave path reflecting off the ionosphere as the radio signal travels from the
    transmitter (in Ottawa, Ontario, Canada) to the user. The time delay is
    3.3µs per km of path, and generally varies by less than 1ms, due to
    uncertainties in path including the uncertainty in the number of skips made
    by the radio wave (reflections down from the ionosphere and back up from the
    surface of the Earth). For a fixed receiver when the number of skips does
    not change, the variation in the path delay will usually be less than 100µs.
    A small additional delay comes from the radio receiver, and may be
    significant.

    Before April 1, 1990, CHU's time announcements were given as Eastern
    Standard Time. Since that time CHU's time announcements have been given as
    Coordinated Universal Time (UTC). The change from EST to UTC was done to
    remain in the spirit of the recommendations of the International
    Consultative Committee on Radio: 'that the standard time broadcasts on
    standard frequencies be given in UTC'. In a narrow sense, since CHU does not
    broadcast on the frequencies allocated for frequency standards, one might
    argue that these recommendations do not necessarily apply to CHU. However,
    since CHU is received across Canada's six time zones and around the world,
    we made the change when it became possible technically to change from EST to
    UTC without difficulty.

    The warble tone at seconds 31 to 39 allow any computer with a Bell 103
    compatible 300 bps modem to receive and decode an accurate source of time.
    The details on the CHU broadcast code can be found here.

    Reception reports from around the world, are gladly accepted from listeners.
    We will respond with a QSL card. Please send reception reports to:

    Radio Station CHU
    National Research Council of Canada
    1200 Montreal Road, Bldg M-36
    Ottawa, Ontario, Canada K1A 0R6

    Or by e-mail to radio.chu@nrc-cnrc.gc.ca




  2. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html


    Max Power schrieb:

    > Re-licencing just might be possible, calling the 7.335 MHz a "broadcast".


    Well, I always thought that stations like WWV and CHU were
    "broadcasts". I mean, they're receivable on any standard radio with a
    shortwave band.

    So the format is "all time all the time". Not really all that
    different from all-news stations like Cuba's Radio Reloj, which mix
    newscasts in between the time-checks all to the sound of a ticking
    metronome.

    All the best for CHU. I would really be dissapointed if they go - I
    always could depend more on CHU's signal than our own WWV. Just better
    reception.

    Stephanie Weil
    New York City


  3. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html


    "Stephanie Weil" wrote in message
    news:1165981388.793918.160520@16g2000cwy.googlegro ups.com...
    >
    > Max Power schrieb:
    >
    >> Re-licencing just might be possible, calling the 7.335 MHz a "broadcast".

    >
    > Well, I always thought that stations like WWV and CHU were
    > "broadcasts". I mean, they're receivable on any standard radio with a
    > shortwave band.
    >
    > So the format is "all time all the time". Not really all that
    > different from all-news stations like Cuba's Radio Reloj, which mix
    > newscasts in between the time-checks all to the sound of a ticking
    > metronome.


    For decades, XEQK in Mexico City gave the time each minute, followed by 11
    5" commercials. You could buy one spot every minute, every two minutes or
    every 4.



  4. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html

    Does anyone know how the definitions of a broadcast and fixed signal
    differ? It sounds like ITU is expanding the number and kind of
    stations that can use that frequency. Implicit within that decision is
    that the time signals from WWV on 5 and 10 mhz could fill the void
    which may not be the case.

    I wonder what the process of re-doing the CHU license for the 7335
    frequency involves and whether they may find themselves competing with
    other signals. Best solution might be to shift to a nearby frequency.


    > Max Power wrote:
    > NRC Short Wave Station Broadcasts (CHU)
    > http://inms-ienm.nrc-cnrc.gc.ca/time...adcasts_e.html
    >
    > NOTICE:
    > About the New Messages on CHU - October, 2006
    >
    > The added messages on CHU are:
    >
    > "On April 1, 2007, CHU needs to stop operating, change frequencies, or
    > re-licence. Contact radio.chu@nrc.gc.ca or mail CHU Canada K1A 0R6," and
    >
    > « En avril 2007, CHU doit soit cesser ses opérations, soit changer de
    > fréquence, soit renouveler sa licence. Contactez radio.chu@cnrc.gc.ca ou
    > écrivez à CHU Canada, Conseil national de recherches, K1A 0R6. »
    >
    > This outreach is to collect information from users of CHU to help shape
    > recommendations concerning what should be done concerning changes to CHU
    > that will have to be in place by April 2007.
    >
    > In April 2007 the licence on 7.335 MHz will have to be modified to reflect
    > changes on the status of the band allocation by the International
    > Telecommunications Union. This frequency has been changed from "fixed
    > service" to "broadcast". (The ITU decision does not affect the frequencies
    > 3.33 MHz and 14.67 MHz.)
    >
    > Some alternatives are:
    >
    > Re-licencing just might be possible, calling the 7.335 MHz a "broadcast".
    >
    > It is also possible to stop using that frequency (the most useful of the
    > three we use). Stopping one signal is the easiest solution but could create
    > problems for some clients who are counting on this particular signal.
    >
    > Change the frequency from 7.335 MHz to a nearby fixed-service frequency. It
    > would need some investment from our part in new hardware and in manpower.It
    > could also create problems for clients, and likely not all radios will be
    > able to tune to the new frequency.
    >
    > Closure of the entire CHU operation, as discussed below.
    >
    > To be seriously considered, any of the above alternatives will need to have
    > a zero-based budgeting justification prepared, comparing it against the
    > least expensive alternative of closing CHU entirely. CHU is entering a phase
    > where major investment in new transmitters will be required if it is to be
    > kept operating. In the absence of input from the CHU user community,
    > concerning the importance of CHU's contribution in the modern world, this
    > last option is an inescapable recommendation.
    >
    > The CHU code is also used as a radio clock, which can be used as a reference
    > clock for an NTP time server. Software drivers have been written that can
    > obtain the date and time from the code and that tune a digitally tuned radio
    > to one of our 3 frequencies, to get the best signal. Users of this service
    > generally don't listen to the audio broadcast. So we cannot gauge the usage
    > by sending this announcement.
    >
    > Please, if you know of anyone using CHU but not aware of the possible
    > changes to its frequency usage, let them know and ask them to contact us
    > about any essential uses. Also if you have an important use for CHU signals,
    > please tell us how you use our signals.
    >
    > We are preparing the case to keep CHU in operation.
    >
    > CHU Time Service
    >
    > Time accuracy superior to telephone time accuracy is available throughout
    > Canada and in many other parts of the world by means of NRC's radio time
    > signals broadcast continuously from short wave radio station CHU. If
    > corrections are made for the propagation delay from CHU to the user, and for
    > delays in the user's receiver, an accuracy of better than 1 ms can be
    > obtained. Signal availability at a user's location depends on ionospheric
    > conditions. CHU also broadcasts a time code which can be decoded with common
    > computers and modems.
    >
    > Three frequencies are used: 3330, 7335, and 14 670 kHz. The transmission
    > mode, upper single sideband with carrier re-inserted, provides time signal
    > service without requiring a special SSB radio, and also provides three
    > standard frequencies. The frequencies are derived from one of a trio of
    > closely synchronized atomic clocks located at the transmitter site. Three
    > clocks are employed to permit majority logic checking. CHU time signals are
    > also derived from these clocks. The clocks at the CHU transmitter site,
    > about 20 km from NRC's time laboratory, are compared daily with the NRC
    > primary cesium clocks.
    >
    > Normally CHU's emission times are accurate to 10-4 s, with carrier frequency
    > accuracy of 5x10-12, compared to NRC's primary clocks, which are usually
    > within 10 microseconds and 1x10-13 compared to UTC. UTC is the international
    > official time reference. It is constructed by the Bureau International des
    > Poids et Mesures (BIPM), based on the average of laboratory and commercial
    > atomic clocks located in laboratories around the world. It is steered in
    > frequency using the primary cesium standards (such as those at NRC) located
    > at some of the major time laboratories. UTC loosely follows the
    > irregularities of the astronomical time scale UT1, which is needed in
    > astronomical observations and in celestial navigation. Since 1972, leap
    > seconds have been used to keep UTC within 0.9 s of UT1. The difference [UT1-
    > UTC] is called DUT1, and this fraction of a second [-0.8 s to +0.8 s] is
    > broadcast by means of an internationally accepted code. To decode the size
    > of DUT1, in tenths of a second, a user counts the number of emphasized
    > seconds markers in one minute. For CHU, the emphasized seconds pulses are
    > split, so that a double tone is heard. When the emphasis is on seconds 1
    > through 8, DUT1 is positive; and when DUT1 is negative, seconds 9 through16
    > are used.
    >
    > The first minute of each hour commences with a full 1 s pulse of 1000 Hz
    > tone, followed by 9 s of silence, and then the normal pattern of 0.3 s
    > pulses of 1000 Hz at one-second intervals. The normal pattern for each of
    > the next 59 minutes starts with a 0.5 s 1000 Hz pulse, followed by the DUT1
    > code employing split 0.3 s pulses where required, and normal 0.3 s pulsesup
    > to and including that at 28 seconds. The pulse at 29 seconds is omitted.
    > Following the normal pulse at 30 seconds, for a 9 s period, 1000 Hz pulses
    > of 0.01 s occur, each followed by the CHU FSK digital time code describedin
    > CHU Broadcast Codes. The pulses between 40 and 50 seconds are of normal
    > length. In the final 10 s period of each minute a bilingual station
    > identification and time announcement is made, with the 1000 Hz seconds
    > pulses shortened to "ticks". Each minute's announced time refers to the
    > beginning of the pulse which follows. Since April 1, 1990, the announced
    > time is always UTC.
    >
    > The CHU station is located 15 km southwest of Ottawa at 45º 17' 47" N, 75º
    > 45' 22" W. Main transmitter powers are 3 kW at 3330 and 14 670 kHz, and 10
    > kW at 7335 kHz. Individual vertical antennas are used for each frequency.
    > The electronics systems feeding the transmitters are duplicated for
    > reliability, and have both battery and generator protection. The generator
    > can also supply the transmitters. The announcements are made by a talking
    > clock using digitally recorded voices.
    > Historical Information
    >
    > Radio station CHU is operated by the Institute for National Measurement
    > Standards at the National Research Council of Canada.
    >
    > The call letters CHU were first used for Canadian time transmission in 1938,
    > on the modern frequencies, 3330 KHz, 7335 KHz and 14670 KHz. Before that the
    > call letters of essentially the same transmissions were VE9OB. The carrier
    > frequency has been the specified standard since 1934; before that the quartz
    > oscillators had been tuned to standard wavelengths. Continuous transmissions
    > at a wavelength of 20.4 m had started in 1933, joining the 40.8 m and 90 m
    > transmissions, which began in 1929 (daytime only).
    >
    > Daily transmission on a wavelength of 52.5 m had begun in 1928 under the
    > call letters 9CC (later VE9CC), but ceased with the startup of 40.8 m
    > operation. 9CC had started experimental time transmission in 1923 on 275 m,
    > and license 3AF had operated in 1922. Thus there is quite a range of
    > possible dates to assign to the establishment of CHU; we lean towards 1929
    > as being the start of daily time transmissions at essentially the modern
    > frequencies. Of course there has been quite a change in equipment and
    > accuracy over the years, but the largest improvement was with the change to
    > cesium atomic clocks in 1967. In 1970 the responsibility of operating CHU
    > was transferred from the astronomers at the Dominion Observatory, to the
    > physicists at the National Research Council.
    >
    > Since 1970, the National Research Council has been charged with maintaining
    > official time for Canada. The short wave radio station CHU is one, but only
    > one of the ways that official time is disseminated across Canada.
    >
    > Following internationally accepted recommendations, Canada and other
    > countries have official time scales in agreement within 10µs. Since CHU's
    > transmissions are well within 100µs of official Canadian time, for all
    > distant users of CHU, the dominant source of time error comes from the radio
    > wave path reflecting off the ionosphere as the radio signal travels from the
    > transmitter (in Ottawa, Ontario, Canada) to the user. The time delay is
    > 3.3µs per km of path, and generally varies by less than 1ms, due to
    > uncertainties in path including the uncertainty in the number of skips made
    > by the radio wave (reflections down from the ionosphere and back up from the
    > surface of the Earth). For a fixed receiver when the number of skips does
    > not change, the variation in the path delay will usually be less than 100µs.
    > A small additional delay comes from the radio receiver, and may be
    > significant.
    >
    > Before April 1, 1990, CHU's time announcements were given as Eastern
    > Standard Time. Since that time CHU's time announcements have been given as
    > Coordinated Universal Time (UTC). The change from EST to UTC was done to
    > remain in the spirit of the recommendations of the International
    > Consultative Committee on Radio: 'that the standard time broadcasts on
    > standard frequencies be given in UTC'. In a narrow sense, since CHU does not
    > broadcast on the frequencies allocated for frequency standards, one might
    > argue that these recommendations do not necessarily apply to CHU. However,
    > since CHU is received across Canada's six time zones and around the world,
    > we made the change when it became possible technically to change from ESTto
    > UTC without difficulty.
    >
    > The warble tone at seconds 31 to 39 allow any computer with a Bell 103
    > compatible 300 bps modem to receive and decode an accurate source of time.
    > The details on the CHU broadcast code can be found here.
    >
    > Reception reports from around the world, are gladly accepted from listeners.
    > We will respond with a QSL card. Please send reception reports to:
    >
    > Radio Station CHU
    > National Research Council of Canada
    > 1200 Montreal Road, Bldg M-36
    > Ottawa, Ontario, Canada K1A 0R6
    >
    > Or by e-mail to radio.chu@nrc-cnrc.gc.ca



  5. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html


    David Eduardo schrieb:

    > For decades, XEQK in Mexico City gave the time each minute, followed by 11
    > 5" commercials.


    Ahh... 1350 AM, La Hora Exacta. They're still trucking along.

    http://www.imer.gob.mx/EstacionesIMER/XEQK/

    steph


  6. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html

    On Tue, 12 Dec 2006 13:24:41 -0800, "Max Power"
    wrote:

    >
    >NRC Short Wave Station Broadcasts (CHU)
    >http://inms-ienm.nrc-cnrc.gc.ca/time...adcasts_e.html
    >
    >NOTICE:
    >About the New Messages on CHU - October, 2006
    >
    >The added messages on CHU are:
    >
    >"On April 1, 2007, CHU needs to stop operating, change frequencies, or
    >re-licence. Contact radio.chu@nrc.gc.ca or mail CHU Canada K1A 0R6," and
    >

    Around the late '60's and early 70's the MIT dorms phone system had a
    time phone number which reached a shortwave receiver tuned to a CHU
    frequency. The frequency was never changed so it only worked at
    certain times.

    --
    Posted via a free Usenet account from http://www.teranews.com


  7. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html


    "Stephanie Weil" wrote in message
    news:1166023693.446538.277250@80g2000cwy.googlegro ups.com...
    >
    > David Eduardo schrieb:
    >
    >> For decades, XEQK in Mexico City gave the time each minute, followed by
    >> 11
    >> 5" commercials.

    >
    > Ahh... 1350 AM, La Hora Exacta. They're still trucking along.
    >
    > http://www.imer.gob.mx/EstacionesIMER/XEQK/


    But they do not run commercials any more... IMER has managed, as usual, to
    mess up a good thing.



  8. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html

    hjsjms@cs.com

    The ITU has allocated the band 7300-7450 kHz for broadcasting in all
    three regions of the world. The band 7450-8100 kHz is allocated for the
    fixed/mobile services, so Canada could in principle move CHU to some
    frequency in that band. North of 8100 kHz are huge blocks of maritime
    and aviation channels. However, in typical ugly American fashion, that
    band is allocated by the FCC in the US for broadcasting (47 CFR Part
    2.106). Even now, CHU has to contend with loudenboomer splatter from
    cochannel and neighboring channel broadcasters. Moving north of 7450 kHz
    might have the same problem, and that from south of the border.

    One alternative might be to move CHU south of the 40-meter amateur band.
    There is a 6765-7000 kHz band allocated for the fixed/mobile services.
    However, the FCC considers that an ISM band, so various kinds of evil
    emitters are sure to be found. Tonight I found a S9+20 dB religious
    program on 6855 kHz broadcasting from Florida, no doubt registered as an
    ISM emitter. Don't get me going on Part 15 and Broadband over Power Line.

    The dillema CHU faces is quite serious. The ITU has allocated 10 kHz
    channels at 2.5, 5, 10, 15, 20 and 25 MHz for standard frequency
    broadcasting. However, shortwave broadcasters are camping on +-5 kHz
    carrier spacing on 5 MHz at least, so their sidebands sometimes clobber
    the WWV transmission, contrary to ITU and FCC rules. There is no other
    frequency that is protected from the broadcasters or vested interests.

    The unvarnished fact is that CHU has been a valuable service in the
    eastern US and Canada where WWV signals are often weak and unreadable.
    And, sad to say, WWVB service at 60 kHz has become seriously degraded
    due to noise pollution via the power lines and uninterruptable power
    sources (UPS). My experience with the NTP audio demodulators for WWV and
    CHU suggest that they may in fact become the preferred alternative after
    GPS, which has its own antenna issues.

    Dave

    hjsjms@cs.com wrote:
    > Does anyone know how the definitions of a broadcast and fixed signal
    > differ? It sounds like ITU is expanding the number and kind of
    > stations that can use that frequency. Implicit within that decision is
    > that the time signals from WWV on 5 and 10 mhz could fill the void
    > which may not be the case.
    >
    > I wonder what the process of re-doing the CHU license for the 7335
    > frequency involves and whether they may find themselves competing with
    > other signals. Best solution might be to shift to a nearby frequency.
    >

    ....>

    >
    >


  9. Re: CHU Public Notice : http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html

    On 2006-12-13, Stephanie Weil wrote:

    > All the best for CHU. I would really be dissapointed if they go - I
    > always could depend more on CHU's signal than our own WWV. Just better
    > reception.


    Why don't you tell them that rather than just hoping for the best?

    --> radio.chu@nrc.gc.ca

    --
    Steve Kostecke
    NTP Public Services Project - http://ntp.isc.org/

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