Antennas for System BLUE - Mini Guide
#8
Don't be sorry to ask Smile
The original 180cm was also made by me, but for an amp with much lower gain, and there it made sense (The GREEN System)
All antennas in the "mini guide" are made for long distance.

A loop antenna reach its maximum signal with the narrow side against lightning and minimum with the broad side against lightning.
Between, the signal = cos(angle) - At 45° angle, the signal is dropped to ~ 71%
Since the antennas is 90° relative to each other, the other antenna is now also at a 45° angle to the signal, and the signal on it is now also decreased to ~ 71%
When the signal fall of one antenna, it increases on the other.
With 3 antennas in a 60° layout as shown by the three ferrite antennas, the signal can fall to ~ 87% before one at the other antennas takes over.
71% or 87% does not matter in practice, so I use two antennas in an perpendicular arrangement.
Direction relation to true north, is unimportant - Personally, I aim my antennas are NS / EW

The third loop we are not finished discussing, in fact we are only just beginning  :-)
As with so much else in this project, the third channel joined because it was possible.
We know that some nearby lightning has a horizontal signal, but at long distance they are damped pretty much.

To investigate what happens to the near-by lightning, we must use a horizontal antenna, and that is WHY it is a good idea Smile
Do you have the desire and time, make a third as you place completely horizontally - let it be exactly the same size.
1-2 is channel 1
4-5 is channel 2
7-8 is channel 3
3,6,9, used for shielding
The vertical antennas has no need to sit in a cross. In fact, it is possible to position three antennas so they can easily reach the amplifier.
It is not a requirement for coaxial loops that they have very short wires to the amplifier. Since they are terminated with impedance of the cable, they can be quite long

/Richo
Stations: 584, 585, 2017
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Messages In This Thread
RE: Antennas for System BLUE - Mini Guide - by RichoAnd - 2016-06-12, 10:29
Wire length E-field - by Ronnyaj - 2016-06-19, 12:28

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