The case is that your posts do not follow time causality principle. They just appear in between the posts that have already been posted several minutes before
Please ask SY to correct this invariance.
Geometry of twisted pair results in partial interference cancelation. Polarity of the induced interferention is oposit in consecutive half-turns.
Sorry been away. Good news the test set up was still sitting untouched on my bench. Results are:
.001" aluminum foil alloy 2024 No decrease in measured level!
.062 aluminum 5052 same result
.125" aluminum 5052 more loss
2 pieces .125 aluminum 5052 (touching) even more loss
Using a hall effect sensor shows the same results! But It is not calibrated so I cannot give exact values. However all the ratio's from induced voltage in the coil vs Hall effect sensor out are the same.
The capacitance between the coils is on the order of e-12 farads. The resistance of the pickup coil is less than .05 ohms. So the "Electrostatic" coupling should be extremely low.
No it is pretty clear the losses are eddy current. You are certainly welcome to try your own measurements.
Whether or not it has a greater loop AREA depends on spacing.
A 10 cm length of wire spaced 1 cm apart is 10 cm sq in loop AREA.
Assuming twisting adds 1.5 times the wire needed for a given running length:
A 15 cm length of wire spaced .1 cm apart has 1.5 cm sq of loop AREA.
These numbers are obviously exaggerated to show how AREA can greatly increase with spacing. It is the AREA that matters, not the total running length of wire.
Therefore, a twist can minimize loop AREA for hum pickup in the first place, and make the loop sizes consistant. True, the reversals cancel what pickup is made, but AREA determines the amount of pickup in a loop.
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I remember your layouts.
It always interested me the way you
used all right-angle turns on the traces.
( I always strived for as gradual of curve
as possible )
( In order not to jerk the electron flow
Right angles on PC traces become a problem with thin traces. Most of the copper is removed as the etchant reacts with the unprotected surfaces, but there is always some side or undercutting action. The corners catch more etchant in some processes. This can result in thin spots or even opens.
If colloidal silver can cure anything, think what colloidal platinum can do!
John
Samuel Christie made what is now called the Wheatstone Bridge, the first balanced circuit around 1833!
Great.
Now let's compare apples to apples instead of apples to oranges.
Take a pair of insulated wires with a given outside diameter.
Run them parallel right next to each other for a length of say 1 meter.
Now take another pair of the same insulated wires and twist them together again for a length of 1 meter.
The twisted pair will have the greater loop area.
se
I have a friend (whos ears I trust very much)
(way more than mine)
He says right angle traces sound bad because
of the "lack of smoothness" brought on by the
electrons changing direction so abruptly.
That's assuming you use the same SPACING for each, which is not likely for a PRACTICAL twisted pair vs. a coax, for example. But since, as usual, you HAVE to have the last word, you can make up another scenario and argue with yourself. Since it is clear that reverse loops affect the cancelling, I am done with this topic.
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