Teisco Gold Foil repair

fixing a vintage Gold Foil pickup

I bought this ’60s made in Japan Gold Foil on eBay “as-is” with the intent to repair it.  It had no output and showed no resistance on the meter so I took the cover off by removing the phillips head screws on top.
Next I removed the magnets which are simply held in place by their own magnetism on either side of the coil.  They were installed with South polarity facing up.  As I was inspecting the coil, I removed some tape and noticed the tiny 44 gauge coil wire had become detached from the white lead wire.  I resoldered and checked the resistance, it was now showing 5.3K.
This might seem like a low resistance for a single coil, but don’t be fooled!  The low resistance makes these nice and clear while the powerful magnets and the squatty coil make it sound full and fat.  I have repaired another Teisco Gold Foil that was around 6.3K and I have seen DeArmond pickups showing upwards of 10K, so there is quite a variance in specs of what is called a “Gold Foil”.  I based my own Humbucker-size Gold Foil pickups on vintage pickups I see come into the shop.
When dealing with classic pickups like this, it is always better to use the original coil if possible for the most authentic tone.  The most common cause of dead pickups I see is sweat or moisture corroding the coils.  Usually there is no other way to repair a corroded coil than to rewind it, which I will do with vintage-spec wire to the appropriate number of turns.  Rewinds usually cost about $50 per coil.
With this pickup I will probably wax pot it so that it will be less microphonic and install in a Telecaster.  Here is a quick video I made of the pickup in my tester guitar:



 

Potting Pickups

Wikipedia defines microphonics as “phenomenon where certain components in electronic devices transform mechanical vibrations into an undesired electrical signal (noise).” The desired function of a guitar pickup is to turn the vibration of the strings into electrical signal. The pickup is basically magnetic pole pieces wrapped with thousands of coils of copper wire, if the copper wire or any other metal part in the pickup vibrates against itself it creates a screeching noise through the amplifier. Microphonics are not our friend, but they can be minimized by dipping the pickups in wax.

The process is fairly simple, but certain safety precautions have to be taken to avoid being burned by the hot wax or catching fire. Wax and the vapors it puts off are extremely flamable and should never be in the vacinity of open flame, that’s why you can’t melt the wax over your kitchen stove, and never try to heat it in the microwave. Use good ventilation.

The first thing you’ll need is a deep fryer designed for home use, these can be fairly inexpensive and all that is required is that it has an adjustable temperature setting. You will also need a thermometer that measures at least up to 150 degrees.

You will also need about a pound of canning paraffin wax and one-quarter pound of beeswax, you can find these at a hardware store or a hobby shop, call first though because this is not always something stores keep in stock.


Set your deep fryer to somewhere around 150 degrees (mine only has settings for 0-225-300-350-390, so I set it somewhere between 0 and 225 and watched the thermometer.) According to Lindy Fralin, a professional pickup winder, the mixture should be four parts paraffin to one part beeswax, so drop in one pound of paraffin and one-quarter pound beeswax.

When the wax is completely melted and the temperature is consistantly 150 degrees you can drop in the pickups, try to keep them from touching the bottom of the pot because that can be hotter than the wax, so put the pickup in the fryer basket or on top of a layer of marbles a the bottom of the pot.

Let the pickups set in the hot wax for about 10-20 minutes and pull them out. Set them somewhere to cool and when they are cool enough remove the excess wax with a soft cloth. They are ready to install and should play with very little noise.