|On 19 Jan 02 the call came in -- Tommy had a killer 1963 Gibson SG Standard but the front pickup, a Patent# humbucker, was not working and was reading dead on the volt/ohm meter (VOM). He asked if I could fix it, and told him I would give it a try and get back to him. Here is how it went down...|
The patent number pickup as shown here is in reality a good old Patent Applied For (PAF) pickup with a different sticker on the bottom. Some of the 1963 SGs actually had PAFs, but the SG this one came out of was just a little later down the line. Seth Lover said in an interview that the patent number was actually that of a Gibson bridge, not a pickup at all. This deception was meant to confuse those wanting to order patent drawings.When I got the pickup it had already been taken out of the guitar and the cover had been removed. The solder joints had been cut. I could not get a reading on the pickup from the lead, so I decided to check each coil individually.
Note corrosion on the screws in the top photo, and the patent number sticker on the bottom. A great pickup.
|I checked each coil for resistance before I removed
them from the base. After the checks, it was clear that the "slug" coil on
the right was OK, while the "screw" coil still shown on the base was dead.
I decided that the dead coil might just have a bad lead, so I needed to remove it from the base.
Note the maple spacer on the left that sits under the slug coil.
I left the large photo below for illustration. You can see the metal spacer here, the magnet, and how the coils are connected. Interesting things to note:
1. Both wires from the pickup were black! The inner winding exits from the bottom of the coil, and the outer winding ends on the inside side of the coil.
2. Slug Coil: The inner winding exits through bottom of the coil. It is attached to the hot out of 2-conductor lead. The inner winding of the screw coil was soldered to the baseplate. Outer windings of each coil joined together for the series link.
3. I unsoldered the series link and the slug coil was OK. It read 4.06 k ohms. About right for a PAF.
|I removed the four brass
screws that held the coils to the base. The screws were Phillips head and had the
I removed a single maple spacer under the slug coil.
Metal Spacer. The shiny side was down, with the beveled edge toward the hole where the lead hoes through the base. 8 Holes in the spacer: six for pickup screws and two for mounting screws. Measurements are:
Magnet: Two little round casting marks on the top. Beveled edge toward hole where conductor goes through base.
|The screw coil had a clockwise wind. It
was clear that I had to attempt to unwind it. I tried to resolder the outside lead, but
the coil was dead. The wire was almost totally black (not blue/purple as I expected), and
very corroded. It appears that something (a liquid) got in the screw side and corroded the
wire. It is probably broken in several places.
I decided to rewind the bad screw coil with 42 AWG wire like the original. When I removed the wire, the coil was completely corroded. The corrosion looked like the corrosion seen on an old battery terminal. The wire was fused together -- no wonder the coil was dead. I used a little naphtha on a Q-Tip to clean the inside of the bobbin. It was a mess!
I finished winding the coil, and it was reading 4.03k ohms. This was within 1%, so I decided to stop -- I got about 4600 turns on the coil. I used the Seth Lover method -- "Wind it till it's full."
I saved the old tape and used it to rewrap the rewound coil. It was very sticky and went right back on.
|I put the pickup back together and checked it
on a test guitar. It sounded great.
As a technique, I checked its hum level next to a nearly new Gibson PAF reissue. The rewound pickup was quieter or as quiet as the new PAF.
Note I didn't clean the tops of the screws -- wouldn't want to hurt its appearance.
|I replaced the cover and soldered it to the
base. I rechecked the pickup to ensure it was working properly with the cover.
Whew...the pickup is complete. Time to reinstall it in that killer SG!
|Complete! I reinstalled the pickup in
the guitar and it just sounded great. The front pickup was as quiet as the back one,
and they had a great, balanced tone together. A complete "woman tone"
A fine playing and great looking old SG, this is one of those you wish you could keep!