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Heterodyning
By Rocky Weeks
This tip requires a bit of radio theory and brain-work. The subject is heterodyning. A very basic definition is two different frequencies that are combined to produce two new frequencies: the sum and difference of the two original frequencies. What does this have to do with traditional archery equipment? Well, knowing this fact helps us to quiet our bows.
Most of us have tried various types of string silencers. Some folks have trouble getting any of them to work. Here is the solution, no matter the type of bow or type of silencer material. Measure the distance from where the string leaves the bow limbs top and bottom. Divide that distance by four and also by three. For instance and simplicity let us say your measured length is 60 inches; divided by four equals 15 inches and divided by three equals 20 inches.
Attach your top string silencer 15 inches down from where the string leaves the bow, and attach the bottom silencer 20 inches up from where it leaves the bow. Doing so cancels out the sustaining frequencies that would make a naked string hum or twang when released. The quartering distance (15 inches) cancels out all even multiples of the frequencies and the distance in thirds cancels out all the odd multiples of the frequencies. The end result is a string that resists vibration after the shot and goes thump instead of twang.
By the way, the same principle applies to whistling broadheads. Using a thin strip of fine sandpaper to buff the leading edges of the rear of the vent cutouts kills the sharp edges that create the whistle. Sometimes only one vent has to be done, sometime one a bit more than the other.