HF found useful

Discussion in 'General Announcements' started by W1CTC, Aug 8, 2017.

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  1. KI6EFA

    KI6EFA Ham Member QRZ Page

    i'm glad that the military has finally learned that these "high frequency" waves have unusual propagation characteristics. hopefully this leads to more advancements in the world of wireless
     
  2. KI6EFA

    KI6EFA Ham Member QRZ Page

    don't they already have all sorts of incredibly obnoxious-sounding OFDM modems? why do they need to announce this
     
  3. WA4ILH

    WA4ILH Subscriber QRZ Page

  4. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Last edited: Aug 12, 2017
  5. SM0AOM

    SM0AOM Ham Member QRZ Page

    24 kHz = 8x3 kHz bandwidth is going to be the first standard for large-scale implementation of "wideband-HF".

    All present major actors in the military HF field have implemented such waveforms for both strategic and tactical HF use.
    The next step will probably be 48 kHz, for which Thales is pushing to be introduced into the NATO HF waveform inventory.

    Practical bandwidth limitations are in antennas, propagation and medium coherence bandwidths.
    With regard ot any ITU limits on bandwidth, there are none, as long as the emission is kept within the limits of the fixed or mobile allocations.

    Besides, the militaries very seldom take any notice of the ITU band allocations.
    If they feel that a frequency or band is necessary, they will operate there.

    73/
    Karl-Arne
    SM0AOM
     
  6. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Yup
     
  7. WA4ILH

    WA4ILH Subscriber QRZ Page

    OK, I agree, some of the old over the horizon radars were nearly that wide. 24 KHz is 8 voice channels. Now that you mention it, there are vast regions of frequencies in the commercial bands that are silent and have been for many years. Has anyone recently heard phone patches being run on the old maritime duplex channels? 25 years ago, they were quite active.
    Tom WA4ILH
     
  8. K4PIH

    K4PIH Ham Member QRZ Page

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