Re: VLF: Changes in MSK usage

[Roger Lapthorn <rogerlapthorn@gmail.com>]

If there really is spectrum being freed up in the LF/VLF regions should we be pressing our governments for further small amateur allocations below 100kHz? For example, how about an allocation at 73kHz (again in the UK) and a band somewhere between 30-40kHz? With the improvements in weak signal techniques in the last few years such allocations would be extremely interesting and ripe for some serious research that would contribute to science, and be a lot of fun.

Regarding Dave Gibson's thoughts on earth electrodes, I'm puzzled. As Stefan says, the current is returned by a path within the soil/rock and a loop MUST exist. Can the structure be modelled both as a magnetic loop and a electric dipole? In my mind I can visualise the loop and how this might work, but I cannot easily visualise the dipole, except as a very short one with a lossy resistance strung between its ends.

73s
Roger

On 22 July 2010 09:15, Markus Vester <markusvester@aol.com> wrote:

Dear VLF enthusiasts,

 

browsing through saved VLF-grabber screenshots, I noticed some recent changes of VLF MSK-band usage:

 

2010-06-24 06:00  20.27 kHz (ICV) QRT
2010-06-30 05:00  16.4 kHz (JXN) QRT
2010-07-05 07:05  18.3 kHz (HWU) QRT
2010-07-08 23:00  21.75 kHz (HWU) break for 6 hours
2010-07-10 06:00  22.1 kHz (GQD) switched from 100 bd to 200 bd
2010-07-10 10:00  19.58 kHz (GBZ) QRT

 

Thus within a couple of weeks, half of the European military signals have gone for good.

 

Perhaps there is less need for submarine communications in today's world... let's hope that the submarines themselves (along with all that other military hardware) may become obsolete in tomorrow's world!

 

73, Markus (DF6NM)

 

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