I recently embarked on upgrades to my Fender Classic Series '70s Stratocaster® Electric Guitar. I noticed how one string was changing pitch after using the tremolo. A worn groove in the bridge saddle was allowing that string to stick. There was also a sticking grove in the guitar nut that would release string tension with a "ping" and thus detune. So I ended up replacing the Fender stamped metal saddles with Graph Tech String Saver Saddles with TPFE (teflon lubricant). I also replaced the string trees and guitar nut with TUSQ XL, also with TPFE, which has the lowest co-efficient of friction of any material. Problem solved.
Next, I decided to address the hum inherent in my vintage single coil pickups. I spent days researching replacement options, including noiseless "humbucker" pickups with an additional reverse-wound coil that cancels the noise. I listened to and read about Fender Vintage Noiseless, Fender Hot Noiseless. Fender N3, DiMarzio pickups, Seymore Duncan pickups, Kinsman pickups, etc. The general consenus from many is that these pickups change the tone compared to the original single coil pickups.
Then I found Ilitch Electronics Noise Canceling System that employs a passive low impedance loop aerial coil built into a back plate or pick guard that senses the hum/noise and cancels it, leaving the tone and chime of the single coil pickups unaltered. As my white pick guard had yellowed significantly due to exposure to UV in sunlight, I opted for the Pick Guard Noise Canceling Systems for Strat (PGNCS-S). After moving all the pickups, potentiometers and 5 position switch to the new pickguard and wiring it up, it was a simple matter of adjusting two trim pots to reduce hum and noise to the minimum. You can use your ears to find the minimum. I also used a spectrum analyzer to visually see the minumum hum points between bridge and neck pickups.
Results? Hum is significantly reduced to the point of inaudible at normal gain. Even when you crank up the gain by adding compressors, maximizers, and effects, the hum is effectively gone – only the hissy noise of additional gain stages is present. For the first time, I can let notes ring out and fade without hearing annoying hum! The pickups themselves sound the same as they did before the system was installed, minus the previous hum. It's quite remarkable and a real joy to play the guitar. I've never heard it this clean before!
If you're unsure about replacing your pickups and possibly losing the original tone, chime and quack, I highly recommend the Ilitch Noise Cancelling Systems.