376. What are the rubber washers used for on the pickup height adjustment on old Fender guitars?
It is basically a amber surgical tubing made from a gummed-rubber that had been commonly used for medical purposes. It has measurements of 1/4” OD, 1/8” ID with a wall thickness of 1/8”. It is now commonly used with many types of exercise devices and commonly seen on sling shots.
I like using the rubber tubing for the height adjustment around the screws as it helps reduce the unwanted vibration or feedback that can occur with a metal spring and it helps cushion the pickup in the pickguard or plates such as in a Telecaster. The metal springs are usually made from spring steel that can pull the magnetic field from the pickup and feedback at higher pre-amp or amplifier volumes.

377. What is Vulcanized Fibre and what is it used for?
Vulcanized Fibre is done by gelatinizing several plies of high purity cellulose papers with high internal bond strength. Vulcanized Fibre is a chemically treated material when completed is made into sheets of homogenous fibre that can be cut, drilled, punched, threaded, machined, bent, bonded and deep drawn. The most common used of Vulcanized Fibre has been hand wired circuit boards on Fender Amplifiers and especially the flatwork used for many styles of Fender and Duncan bobbins.

378. What kind of solder should be used when soldering guitar components?
Solder is a combination of tin and lead and has the capability of melting at relatively low temperatures. I’ve always used a 60/40 solder that is 60 percent tin and 40 percent lead and becomes liquid at about 370? F. A 50/50 solder requires about 420? F. All solders when going from solid to liquid change into a plastic state at about 360? F as stated by Robert L. Shrader in the book Electronic Communication. The flux that is in the hollow of the rosin core solder helps clean the metal and allowing a better flow of the solder to the components being soldered together. Acid core solder can eventually eat away at the copper insulated magnet wire causing failure in the coil. Make sure the joints are motionless or the joint can crystallize or become a cold solder joint that can lose its holding ability. Never use an acid core solder that is commonly used for connecting water pipes and sheet metal together when doing home plumbing. The solder must have a lower melting point than the two metals being joined together and capable of uniting the two metals being joined.

379. What kind of soldering iron should I use?
I would use a soldering iron that contains no coil to heat the tip or soldering element. The coil type soldering guns can demagnetize the magnet within the pickup. I like using a Weller Controlled Output Station with three temperatures from 600? F, 700? F and 800? F. I use 600? F the most for soldering eyelet’s and connecting magnet wire from the coil to lead wires as in humbuckers. I use a screwdriver tip as it covers the eyelet better when doing lots of soldering. I use a American Beauty industrial soldering iron especially for removing covers from humbuckers and soldering Telecaster bottom plates. I use American Beauty Model 3138-LT and weights 2 1/4 lbs.

380. What kind of plating is used on pickup covers and hardware?
Most plating used on hardware and components on electric guitars are used to keep the parts from rusting, oxidizing or changing colors. Chrome, Nickel, Gold and Anodizing are the most common and many other types of dull or bright plating may be used. There is Black Chrome, Black Nickel, Black Oxide. Some plating such as Gold or Anodizing may be lacquer coated to add longer protection from wear to the parts.

381. What materials are the Fender style bobbins make of?
Fender style bobbins that are fabricated and combined with rod magnets are commonly made from Vulcanized Fibre and later other Fender bobbins are made from a plastic molded bobbin. Vulcanized Fibre is made Spaulding Fibre, NVF and Toyo Fibre. Vulcanized Fibre is great to work with and can be punched out into many shapes. Music Man, G & L, Seymour Duncan all use some form of Vulcanized Fibre for their fabricated bobbins. Fabricated means a combination of flatwork, magnets, spacer etc. to form a working bobbin ready for winding. Nylon bobbins are used on the Fender Humbucker and Bass bobbins and one popular molding plastic is Nylon 6/6.

382. What materials are the molded bobbins make of?
There are many types of material that can be used for making bobbins such as High Pressure Styrene, Butyrate, Nylons, Glass Filled Nylon, Phenolic (Bakelite), Polycarbonate, Polypropylene, ABS, PVC etc. There are several other factors that determine what kind of plastic you want to use. Some are the cost per piece, the color and surface finish, the tolerance, impact to wear and abrasion. Materials used for making bobbins can be molded in various colors and custom plastic shops can match the color to your specific needs.

383. Where did you get your first material for a guitar pickup?
The first material I found for fabricating guitar bobbins came from old drum cases made from Vulcanized Fibre. I got my first Vulcanized Fibre from Jim Sharp, the drummer in one of my first bands called “The Flintones” in Gibbstown, New Jersey during the 60’s. Most cases where 1/16” thick and just right to fabricate the parts need to make several models of pickups. I could make Gibson style P-90 bobbins and many styles of Fender pickups. All done with a pair of metal cutting shears, files, center punch, drill press and drills for the desired hole diameter. I would rough out the parts and square the edges with a block of wood and sandpaper. I don’t think my drummer ever appreciated me cutting up his old drum cases but he knew what I was trying to do.

384. Why are laminated blades used for pole pieces?
Laminated bars are used to reduce eddy currents and a core with higher efficiency. In transformers you have higher efficiency with a minimum number of turns using insulated laminated sheets. Eddy currents are decreased in strength by using many thin sheets rather that a solid bar. The sheets should be insulated for optimum efficiency and to keep the laminates from shorting out with each other. Laminated blades have been used on Gretsch, Seymour Duncan custom and Bill Bartolini to retain the higher frequencies in a pickup.

385. What guitars had the first pickups?
There is controversy to this subject which I am currently researching. From around 1920-1924 Lloyd Loar worked for Gibson and some of his early pickups were said to be found by Walter Fuller when he joined Gibson around 1933. Lloyd Loar left Gibson earlier to form the Vivi-Tone company and had taken pickup designs with him. Several players stated that some of the early phonograph cartridges where connected to the guitar to amplify it and around 1931 Rickenbacker had an instrument called the Frying Pan that had an electromagnetic pickup. Here are a few of the early pickup patents that I could find.
2,087,106 Guy Hart-filed Feb. 8, 1936-granted July 13, 1937
Gibson EH-150 Pickup commonly called The Charlie Christian Pickup.
2,089,171 George D. Beauchamp-filed June 2, 1934-granted Aug. 10, 1937
Rickenbacker pickup used on The Frying Pan
2,119,585 A.F. Knoblaugh-filed Dec. 9, 1935-granted June 7, 1938
Stack style pickup.
2,145,490 G.R. Miller-filed April 18, 1938-granted Jan 31, 1939
Adjustable poles for each string using a pole similar to a Gibson Deluxe PU.
2,175,325 H.S. Sunshine-filed Nov. 10, 1937-granted Oct. 10, 1939
A threaded steel polepiece with a larger Pan head screw for wider string vibration.
2,262,335 C.W. Russell-filed July 21, 1939-granted Nov. 11, 1941
A two coil pickup wired in series but still non-humbucking.

386. Who first commercially used pickups as a standard item?
Probably the first commercially that used an electromagnetic pickup was Rickenbacker with the Frying Pan guitar with horseshoe magnet pickup. Dobro and National instruments started becoming electrified even thought the demand was not that great. Around 1935 while working at Gibson, Walt Fuller started making the ES-150 Pickup (Charlie Christian as it is called) and using it on the ES-150 Guitar. At that time the same style pickup with different blades was used on the EH-Electric Hawaiian model lap steel guitars. Many other instruments were adapted with Rowe-DeArmond pickups and others used custom or modified pickups such as Les Paul experimenting with Low Impedance pickups to reduce unwanted noise especially when recording and doing live performances. Many of the early pickups were bulky and heavy due mostly to the magnetic material available for making pickups. Early Alnico magnets and Cobalt Steels were used and could dampen the sustain in the body affecting the tone of the instrument.

387. Who invents the guitar pickups?
Often guitar companies design pickups in house and use engineers to design and work on projects. At times the owner of the company will use his name as the inventor even though they didn’t design the pickup. Often times a pickup design may be used with no patent on the design and later be patented by some other company that applied for it. Often a company will obtain a design from an outsider and patent it themselves. There are several guitar pickup designs with no patent and it seems the pickups are in public domain. Often a patent on a pickup will run out in 7 years depending on the type patent issued. Refer to question # 121 for some of the early pickup designs and future articles will have other pickup designs and patent numbers.

388. What are the specifications for a Patent Applied For humbucker?
This is the nickname given to the original Gibson Humbucking pickup designed by Seth E. Lover. The patent was filed on June 22, 1955 and granted on July 28, 1959. The actual pickup patent number for the pickup is 2,896,491. On the patent application it's called a "MAGNETIC PICKUP FOR STRINGED MUSICAL INSTRUMENT". Some of the principal objects of the invention are:
First, to provide a magnetic pickup for a stringed musical instrument which is not affected by adjacent electrical devices and which does not pick up and transmit to the amplifier the hum of such devices.
Second, to provide an electromagnetic pickup for stringed musical instrument with magnetically opposed pickup coils that neutralize the effect of currents induced by adjacent electrical devices.
Third, to provide a hum neutralizing magnetic pickup that is efficient in producing electrical vibrations in response to the playing of a stringed instrument.
Fourth, to provide a magnetic pickup that effectively employs relatively small masses of permanent magnet material and is easily mounted on a stringed musical instrument in proper relation to the strings of the instrument.
Fifth, to provide a magnetic pickup having a metallic magnetic return circuit between a pole of the permanent magnet and a coacting string of a musical instrument to increase the strength of the magnetic field around the string and improve the efficiency of the permanent magnet.

389. What happens to the sound of a pickup, keeping the pickup low and raising the poles?
This is a trick I’ve seen Jeff Beck do on a guitar I built for him during the 70’s. It was nicknamed The Tele-Gib and he used in on songs like “Cause we’ve ended as lovers” and he was seen playing it on the “Secrets Policeman’s Ball” video. He would lower the bridge pickup about 1/4” from the strings and raise the adjustable pole pieces to about 1/16” from the strings. This would give him extra bite without the sound being to fat or full and still be humbucking. By raising the poles keeps the stud side further away from the strings and not as dirty when the volume in up all the way on the guitar. He could make the guitar cry more when manipulating the volume and tone controls during the intro to the song “Cause we’ve ended as lovers”.

390. What make's a humbucker have a better “Patent Applied For” sound?
The “Patent Applied For” sound can be very subjective and to me, some PAF’s sound O.K. and some sound great. It has much to do with the instrument the pickups are in and the adjustment. The tone of the pickup has much to do with the coil, magnet, position, adjustment, string gauge, DC resistance, number of turns, tolerance of magnet wire in the coil, lubrication of magnet wire for layering, tension, ohms per 1,000 feet, number of turns per layer, the number of layers, the materials, cover, studs, potentiometers, capacitors, resonant of wood, frets, fingerboard density and cable to the amplifier.

391. What modifications can be done to a humbucker?
Some of the common things done to humbuckers are: Make 4 conductor, change the adjustable pole pieces, change the studs, replace the studs with rod magnets, remove the covers, add covers, change the bar magnets, flip the bar magnet to reverse polarity, rewind to different specifications, calibrate the magnet(s), change the length of the adjustable pole pieces, use different screw combinations, use other wiring combinations, series, parallel, split the coils, in or out of phase with itself. There are many combinations and modifications that can be done and look for further modifications due in my future articles.

392. Are Fender and Gibson magnets the same specification today as many years ago?
Magnets manufactured today may have closer tolerances than products made 40 or 50 years ago. Over time the magnet can be altered by age, heat, shock or other outside electrical elements such as transformers or other magnets. Companies try to keep tight tolerances when being manufactured but some are not always kept. When I say a magnet ages, I am saying it can become weaker because of the realignment of the magnetic domains within the magnet. Some think a magnet can’t become weak but they do. Why do you magnetize a magnet anyway? To alien the magnet domains within the magnet. You can reverse the polarity of a magnet too as some think you can’t.

393. Can I change the magnet in my humbucker?
You can flip the magnet over 180 degrees to change the magnetic polarity of the pickup and you can adapt magnets of different materials such as Ceramics, Alnico 5, Alnico 4 and different dimensions to your needs. If you use different magnets, make sure you secure or have the pickup potted to eliminate unwanted feed back from loose or vibrating parts. Any time you modify your pickups will most likely avoid all warranties given by a manufacture.

394. Can magnetic rods be inserted in my humbucking instead of the steel studs?
You can use rod magnets in place of the studs and make sure the correct polarity is proper on the stud side of the humbucker. The stud polarity should be opposite from the adjustable side which is normally South polarity. You should have all the North polarity rod magnets facing up. The pickup will probably sound brighter with the modification of rod magnets properly inserted. If you put the magnets in wrong, the pickup will have phase problems and it can alter the polarity in the existing magnet.

395. Can the magnets be moved in my Fender pickup for better string balance?
Magnet that are pressed into the Vulcanized Fibre flatwork should not be move or adjusted. The beginning of the coil and magnet wire are wound directly around the rod magnets that are pressed into the flatwork. If you try to move the pole pieces for better string balance you can permanently damage the coil from the inside requiring complete rewinding of the coil which can devalue your instrument if not done properly. Most all Alnico rod magnets used in pickup building are sand cast and some are sintered using another process that will be discussed later. Some of the rod magnets are ground to the desired diameter and early magnets used in Fender pickups had a slightly larger diameter and more pitting in the walls. As the coil is wound around the pitted walls, there is more likely damage to the coil if the pole pieces are moved in any way. There is a considerable amount of pressure especially on the end magnets that are firmly held by the turns of the hand wound coil. No not move or realign the pole pieces.

396. Can you change the magnets in a humbucker?
Refer to question # 129 as it will give you some ideas of what you can do with the magnet in your humbucker. Changing your magnet will most likely change the sound in your pickup. If you use a stronger magnet, you will probably hear a little more output and a brighter sounding pickup. If you use a weaker magnet, you will probably hear a warmer sweeter tone. The weaker magnets are my favorite and I’ve often used early Gibson bar magnets from broken pickups in my newer pickups with great success.

397. Do magnets lose strength?
It is a proven fact that magnets can lose strength over time and outside elements such as:
Outside electrical fields: Soldering guns should never be used to work on your guitar electronics or pickup modifications as the coil has a strong electro-magnetic field that can degauss the magnet within your pickups.
Being in contact with other magnetic fields: I’ve always hated seeing displays in stores where the pickups are piled on top of each other as the pickups can interfere with the ones above or below. Never store pickups next to each other as a stronger pickup with a ceramic magnet can degauss or realign the domains in magnets from other pickups.
Hitting magnets: Never tap magnets with metal objects as the shock can realign the domains again in the magnet. Hitting or dropping magnets can change the magnetic domains within the magnets.
Heating magnets: Never grind magnets as the high temperature can affect the magnetic domains in the magnet. Also the grindings can bond to other parts of the pickups and cause later problems.

398. Do the two E strings on electric guitars have the same magnetic field as the A-D-G-B strings?
Basically all pickups with equal pole pieces as the number of strings have a design flaw. If you notice Fender style pickups using 6 Alnico rod magnet pole pieces, the A-5th, D-4th, G-3rd, B-2nd poles each have a magnet on both sides of it. For example the A-5th pole has the E-6th pole and the D-4th magnetic pole pushing against it. On both bottom E-6th and high E-1st there is only one pole along side it producing a different magnetic field for the string vibration in those two positions. A magnet is in a pickup basically to magnetize the string and when the string vibrates, it moves the magnetic field back and forth through the coil and produces an alternating current that travels through the controls to the amplifier. For proper magnetic and electrical phasing all pole pieces should be of the same polarity such as: (S-S-S-S-S-S) or (N-N-N-N-N-N) and never (S-S-S-N-N-N) or (S-N-S-N-S-N) in the same single coil pickup. You could experiment with different pole polarities (North or South) to create different tonalities in the pickup. By changing the magnetic polarity of one pickup can effect the sound when combined with others. Never remove or reverse rod magnets in single coil pickups with fibre bobbins as the coil is probably wound directly around the magnets and removal of the rod magnets can break the inner windings of the coil.

399. How do strings effect the magnetic field in pickups?
Normally the larger diameter of the bottom E (6th) will be louder and much depends on the diameter of the spring steel inner-core and alloy the outer wrapping is comprised of. Usually the larger the diameter of the inner-core the louder the particular string would be. The mass and alloy of the string will also determine the output of each string over a particular pole. That’s why you don’t see the lower strings such as the E-6th, A-5th or D-4th using just a solid core or plain spring steel. The mass of .042”, E-6th string would overwhelm the output of the .009”, E-1st string. A less magnetic material is wrapped around the lower strings for mass and tension. The specifications on the strings that I use are:

400.How are Alnico bar magnets made?
All grades of cast Alnico magnets can be made by Shell or Baked sand molding. Sand casting in “Green” sand is used for larger magnets. The cast Alnico are typically molded in this way too for many shapes and fabrications. Investment casting, also known as lost wax casting, is done when the complexity of a magnet’s shape doesn’t permit Shell or Baked sand molding. The surface of sand cast magnets can either be used stock or machined for proper surfaces or dimensions. Typically a plate of bar stock is molded to close tolerances, cut and surface ground to the customers specifications. There are fewer and fewer molding houses that make bar and rod stock for our applications.