Re: LF: G3ZJO grabber

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Eddie

 

Interesting stuff. I have never looked for the old Project Sanguine signals around 76Hz or Zefs at 82Hz.

 

Somewhere I have an old US Navy or NATO/AGARD paper written in the 1960s entitled "DC Signalling in Conducting Media". This was a paper looking at US military use of slow signalling close to DC through rock strata for highly secured sites.

 

Perhaps I should try some earth mode comms down below 50Hz. I won't suggest radiated tests as Stephan would be tempted to make a TX and connect it to an even larger kite antenna! He'll soon need a helicopter.

 

73s

Roger G3XBM

 

 

2011/5/4 qrss qrss@talktalk.net 

Hello Stefan

I was prompted to take a look 'down low' a couple of weeks ago when SM5LE said, look 'Schumann resonances'. You will be surprised that I am using your E-Probe, unmodified. I wasn't expecting to see much so I was surprised by the results.
Have I seen Schumann resonances? I am not going to say, proof needs time of observation.

Information about the signals and phenomena down there is scarce, I have heard mention of 90Hz for submarine comms so many thanks for the link I have removed my LPF and shifted the window up to take a look on 82Hz.

EDIT
Carrier at 80.2Hz, 75.2Hz and 64.24Hz which would seem to be a harmonic of the 32Hz and likewise the 16Hz a sub harmonic of 32Hz.

My searches for information have certainly taken me to Renato's page, I was showing a link to his site as a 8.9kHz Grabber, since looking at his site I have moved him into a Link class of his own.

There have been questions about the pulses of interference at ULF. When we look at our VLF Wide displays the Sferics seem to peter out around 3kHz, (your filter is doing its job). However I have used the 0....50Hz view to prove to my own satisfaction that Sferics are still going strong down to 0Hz. Probably removing the 3kHz cut of would cause havoc down there.

There are several carriers of unknown origin, maybe due to my urban location which I can investigate. Any thoughts of what runs at 32Hz would be welcome, I am pretty sure it comes down from the antenna. Well, when there are no tests on 8.9kHz I can keep interested.

73 Eddie

On 04/05/2011 12:14, Stefan Schäfer wrote:

Hello Eddie, VLF,

Your additional grabber windows are interesting. Remembers me to the site of Renato Romero ;-)
What antenna do you use for displaying the range of 0...50 Hz? My probe circuit has a high pass filter with an edge frequency of about 3 kHz. So if your QRM below 3 kHz is not to strong, you may remove that and get better signals on ELF. Have you ever received the ZEVS at 82 Hz? http://www.vlf.it/zevs/zevs.htm

73, Stefan/DK7FC

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