SWR and Impedance matching are relevant to Power flow from Source to Load in all AC & RF systems, and not only to antennas or transmitting.
In fact impedance matching applies to DC systems as well, but SWR does not apply to DC, as there is no Wave or Standing Wave in DC.
The “impedance matching for maximum power transfer” was discovered about 175 years ago for DC, when RF was not yet born 
. Around 1840 Moritz von Jacobi published the “maximum power transfer theorem”. It is also referred to as “Jacobi’s law”. It states that “to obtain maximum external power from a source with a finite internal resistance, the resistance of the load must equal the resistance of the source”. Please see details in Wikipedia.
Also, not sure if anyone has pointed this out, the disc capacitor(s) act as a DC block to the antenna, so it will block the DC from the amplifier output of one of those RCA or similar inline amps.
Thanks for pointing out. This is an added advantage, and will eliminate the need for DC Blocker, if the amplifier is installed somewhere between capacitor & receiver.
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