yeah -- not finished

Here's the new hum-bucker coil, with plexiglass brackets to mount it above the signal coil on the little harp.



In the initial test, I was pleased to find that this coil works very effectively, to cancel out a large part of the hum -- I won't say 100%, but pretty good.  I attached it above the "live" coil with blue tape, and temporarily tacked the wires into parallel with the live coil.  I found that in one polarity, the hum was substantially cancelled.  In the other polarity, or when not connected at all, the hum was just about the same: i.e., really bad.  So, this is a success, and I now have the epoxy drying on the "permanent" mounting, with the wires soldered in the experimentally-verified correct polarity.

In the future, for harpsichords and such, I'll try to come up with a two-layer bobbin design that lets me do this with a single unit, like the so-called "stacked single coil" pickups for guitars.  The issue is where and how to place the metal plate and the magnets, which in this current design have ended up in the middle of the sandwich.  Well, this will be a future chapter of the story...


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