I attempted to explain that I've disassembled the humbucker pickup,
separated the 2 coils, and have removed all the metal influences from the
coils.
The magnet, pole pieces, screws, frame plate and cover have been removed and
set aside.

Just a plastic bobbin and hundreds of turns of wire.. there is no metal,
other than the coil of wire.
The desk where I'm checking the coils is wood.

At that point, there weren't even any long signal leads attached to the
coil.

So I've reassembled the pickup as originally wired, with a short pigtail of
shielded pickup coil cable.

I added an inline 1/4" jack to the pigtail, and plugged my VOX AM30 Amplug
headphone amplifier into the pigtail, and held the pickup near the guitar
strings (in the open space between the guitar's neck and bridge pickups..

and Buhh-Zinga! plenty of output from this Epiphone humbucker pickup.

This isn't a definitive performance test, but the notes sound very clear and
strong for all the strings.
I immediately plugged the H-P amp into the guitar, and the Epiphone pickup
sounded essentially the same as the guitar's DiMarzio DP155 bridge pickup.

I hadn't suspected that the Epiphone pickup was bad, but I wasn't sure since
it hadn't been installed in a guitar since I've had it.

BTW, I didn't place the metal cover back on the pickup, and I'm aware that a
metal cover will create a fairly large area for eddy current to pass, and
slightly affect the peak frequency.

I think I'll make a little gantry for suspending test pickups over the
guitar strings, for a quick bench check.

But I still don't know why the Bare coils didn't ring higher than 4 rings.
It's possible that shorted turns could exist even though the output seems to
be OK.

Oh, and forgot to mench.. the inductance measurement for the combined coils
in this pickup (when it's fully assembled) reads about 5.5 H.

--
Cheers,
WB
..............


"Phil Allison" wrote in message
...

"Wild_Bill"

I remembered that the Z-Meter manuals specifically state that these
testers work with inductors with powdered iron/ferrite-type cores (not
steel such as power transformers), so I removed the steel screws, but the
coils still only have 4 rings.


** The pickup has a steel ( possibly Alnico ) magnet and soft iron pole
pieces, this makes for a lossy inductor - bit like a normal loudspeaker
voice coil is.

If you remove all of that, the inductance goes down and you have a low Q
inductor because of the high resistance.


... Phil