Excellent Thread! I have tried to cover this in the Thread: Electromagnetic Waves
I would like to start by saying, there is a massive difference between the interpreted Standing Wave that some think as a Standing Wave. What do I mean? Well we are dealing with two Physical Properties:
Because we have two physical properties, we can have a standing wave of each, Voltage and also of Current, but not the same both at once. The reason is each is manifested differently!
Floyd Sweet made some important statements about this:
Now of course, the reference to a "Team Wave", is a Standing Wave! But there are two different manifestations, the second starting from the paragraph starting with "Similarly".
Voltage Standing Waves have nothing to do with the Magnetic Field, Voltage is already present.
In an Antenna, Standing Waves are well known to be damaging to the transmitted / receiving Signal:
The Feed Cable has standing waves all down the cable, but the Antenna's active element itself is in perfect resonance. If the Antenna's Active Element was not in perfect Resonance, and Standing waves were present, then the Antenna would not Transmit / Receive the signal. Floyd Sweeet said this very well also:
Resonance frequencies may be maintained quite constant at high power levels so long as the load remains constant. We are all familiar with AM and FM propagation, where in the case as AM, the voltage amplitude varies, and with FM, the frequency is modulated.
However, the output power sees a constant load impedance, that of the matched antenna system. If this changes, the input to the antenna is mismatched, and standing waves are generated resulting in a loss of power. The frequency is a forced response and remains constant. Power is lost and efficiency becomes less and less, depending on the degree of mismatch.
Ref: Floyd Sweet - Magnetic Resonance.
Now, Current, the Standing Wave associated with Current is somewhat different! We must have a Magnetic Field Cancellation for the Current Wave to Stand, this is not the case with Voltage!
When we see this image, or a similar image:
We need to think of different things, and ask what might this be? Voltage or Current? Or both?
George's videos are excellent, please don't get me wrong, but I think we are all guilty of not being clear sometimes when we are learning. I know I have been guilty of this, I try my best, always, not to confuse others, but it happens.
George is using LCR Resonance and therefore Voltage Standing Waves, that's what the LED's are indicating, Capacitor Voltage, but at the same time, there is a Magnetic Component because of the Transformer, so there could be both Voltage and also Current Standing Waves present in this machine. Magnetic Resonance can not exist in this machine.
George's basic Circuit is:
I hope you don't mind me pointing this out, as it is very easy for people to get these differences confused.
P.S: Also, we have Single Wire and also Dual Wire situations which are also different.