Hi Martin,
Thanks for a prompt response.
I have been using the commercial made by Aispy Moebius passive anteenna. As you know, this antenna gets supplied with RG402 1 meter coaxial cable limbs terminated with SMA connectors , crossover device at mid point and T-box that contains 1:1 balun.
The secondary winding of RF transfomer ( balun ) is with a center tap that is grounded to same point as shields of coaxial cables meeting the T-box and the secondary winding is connected to inner conductors of coaxial cable limbs.?
I even tried to calculate the resonance frequency of this loop - 1.75 MHz, based on the inductance of 1 meter cable limbs 144.24 nH and capacitance 57 pF. However, from other source I found the resonance frequency should be around?
3.4 MHz ( I am not sure what cable was used and the circumference of the loop in that example ). I have no plans to built and experiment with different loop antennas like a single? unscreened loop of wire.
Let's for sake of argument better focus on your experimental work related to passive loop antennas described in article - " Moebius Loop Antennas, June 2021".?
Regarding this article with your experimental tests I have a few questions:
1. You presented measurement results S21 parameter vs. frequency for a loop loaded with 50 ohms and additionally the Moebius type when terminated in 400 ohms.
? ? You wrote - overall it looks like Moebius type would benefit from a different transformer impedance ratio.?
? ? That is the reason why I asked earlier for a benefit changing the balun impedance ratio allowing my current antenna to see a higher impedance, say 400 oms instead of 50 ohms,?
2. Your Moebius anteena is differently connected to the balun that does not use center taped secondary winding. Why is that ?
Regards,
Raphael
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