(Note: images restored from a backup held on my own computer - enjoy! sumgai)
Pickup Coil Response Tuning
While this is a continuation of my exercise in The Passive High-Cut Tone Control, I want to give full credit to Helmuth E. W. Lemme for his most excellent explanationThe Secrets of Electrical Guitar Pickups of this along with his general pickup technical explanation. I had known of and discussed this theme with him long before I joined, or there was a, GN2. As I was traveling to Europe/Koln for a business conference (Schloss_Gracht) some years ago, I'd wanted to contact him regarding his pickup tester, but my schedule precluded this.
Also note that his switched capacitor product may well have preceded the StellarTone folks.
I will leave the technical explanation to his excellent article, and just post my simulation results since they are just plain pretty.
While the article is fairly technical, it must be read in its entirety to fully appreciate what is afoot here.
A subset of capacitor values for ranges of most interest.
This is one single coil pickup with 5 tuning capacitors, with 0K series resistance;
I use one of these (well, this one too) to tune pickup coils. Since I have an LCR meter (Inductance/Capacitance/Resistance), it's easy to discern the correct value. This one goes from about 100 pF to 1,400 pF (1n4 F). They are found in old (60's or so) AM radios. It's a lot easier to tune with a knob rather than switching caps.
The real beauty of coil tuning this way is that it can be done external to the guitar, without modifying the guitar, until the desired values are ascertained.