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Amateur radio enthusiasts have slices of spectrum at every magnitude of spectrum MF and above, but in the US none are below MF.

Why are there no spectrum allocations below 160M?

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  • $\begingroup$ While not a full answer as to why we don't have a spectrum allocation, here is some information in regards to LF and amateur radio operations. I remember reading of LF experimenters and the hopes to eventually get an allocation. arrl.org/lf-low-frequency $\endgroup$ – Koerner Mar 14 '14 at 15:32
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    $\begingroup$ en.wikipedia.org/wiki/2200-meter_band $\endgroup$ – Optionparty Mar 14 '14 at 23:34
  • $\begingroup$ There is allocation below 10khz, some experiments i'm working on is using huge loops on the ground and ground rods for communication, and I have already had luck up to TWO WHOLE CITY BLOCKS!!!! Using no modulation whatsoever, just audio from a 100Watt HI-FI home stereo system $\endgroup$ – Skyler 440 Mar 18 '14 at 0:29
  • $\begingroup$ @Optionparty en.wikipedia.org/wiki/2200-meter_band#United_States specifically states that there is currently no such allocation in the US, while the question is tagged united-states. $\endgroup$ – a CVn Mar 20 '14 at 10:43
  • $\begingroup$ The 136 kc band was allocated with the CB 28 mc band long ago. As an "Experimental" band. Not specifically for Ham radio. $\endgroup$ – Optionparty Mar 20 '14 at 13:34
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See the US allocation of frequencies for the source data for some of this.

Right now, the current users of VLF/LF are either maritime mobile, radio navigation, time frequencies, or aeronautical use. There are a few stations that have experimental privileges, as ARRL mentions. The bandwidth for these bands drops dramatically, often only a few kilohertz.

As Wikipedia mentions, the reason why the 2200 band isn't available in the United states is:

On May 14, 2003, however, the FCC declined to grant these privileges citing concerns over potential interference with power line communications (PLC) systems operating unlicensed under Part 15 used by electrical utilities to control the power grid. But the FCC added that amateurs wishing to experiment with 136 kHz communications may apply for a Part 5 Experimental License or operate under Part 15 regulations for this part of the electromagnetic spectrum.

See also the FCC ruling directly, which specifically states:

While we agree that amateur experimentation in the 135.7-137.8 kHz and 160-190 kHz portions of the LF spectrum could serve to increase the pool of individuals having knowledge of LF transmissions, we conclude that such operations would pose the potential for harmful interference to systems protecting and controlling the national power grid.

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