On Wednesday, July 18, 2018 05:34:51 PM you wrote:

SNIP

> 
> Perhaps so but now I do not understand how the coupling can be only
> -21 dB. The efficiency of the TX antenna is < 0.1% and surely the
> little RX antenna is very inefficient also. How can I have only 21
> dB loss of signal between them? What is the method of coupling or
> signal transfer for antennas in such close proximity?
> 

Few meters from the transmitting antenna: at those frequencies the "reactive 
field" dominate, so the inverse square law is non applicable.

73 de Claudio, IK2PII
 
 
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