Re: LF: VLF Small magnetic antenna for Tx

[DK7FC <selberdenken@posteo.de>]

Hi Luis,

You seem to generate much activity on all bands in your Spanish region :-) That is fine!

Am 01.02.2018 19:58, schrieb VIGILANT Luis Fernández:

 

As this is the “near field” it is supposed to work only at magnetic field due to the small size of the antenna ? So only magnetic field for

underground signals at this distances ?

The E field also works in the near field of course but through the ground you will have no chance with an underground E field TX antenna :-) Just try it on LF at home :-)

Can we expect to receive the signal with an electric probe antenna in the near field or the only chance is to be further away ?

In the moment i can receive my 970 Hz signal radiated from the E field antenna and received by the H field antenna. But it is not optimal. The signal strength will be higher when using the same type of antenna as long as you are in a range of  < 0.7 * far field distance.

 

Which would be the radiated power of such antenna ?

There are formulas on Rik's websites for 136 kHz, http://www.strobbe.eu/on7yd/136ant/#Loops

73, Stefan