grounding the bridge

[SkuttleFunk]

definitely NOT wanting to get into the debate on whether to ground or not to ground the bridge ...

I have never been satisfied with the traditional method of fraying the ground lead wire under the bridge before securing the bridge to the body. IME, this has always lead to a bridge that doesn't sit completely flush against a body made with a harder wood top (think ebony, rosewood, birdseye maple in contrast to swamp ash an mahogany)

One easy way to remedy this is to utilize a section of adhesive backed copper shielding foil. Cut a strip narrow enoug to fit into the routed divit under the bridge and long enough to cover the bottom of this divit, its sides, and across the body to within 1/8" of the bridge plate edge. Attach the shielding foil, run the grounding lead into the cavity, and then solder the grounding lead to the foil in the bottom of the divit. Now when you install the bridge it will be flush with the body and you'll have a greater contact area for the ground. You will also never need to wonder if the grounding lead wire is in contact with the bridge.

If this is not entirely clear, I can always shoot an image of my next bridge install and provide it in a follow-up post in this thread

all the best,

R

 

[GearBoxTy]

Yea, post a pic.  This sounds like a great idea, but I think it would be clearer with an image or two.  Maybe the whole process!

 

[neil]

didn't fender do something similar on early jazz basses....the copper strip from bridge to first pick up cavity?

 

[Alfang]

Of course your talking about fixed bridges right?

Where would you ground a tunamatic style bridge

John

 

[Shmoopie]

yeah id like to see how thats done.

 

[bootlegger]

Of course your talking about fixed bridges right?

Where would you ground a tunamatic style bridge

John

On the post bushing before you put the post in the body.  There is (should always be) a hole from you rear body cavity to the post bushing hole.  You can solder it to the post bushing before you press your bushing in.  Run your ground wire through the body cavity and through the bushing hole. Solder the ground wire to the bushing leaving enough wire as not to pull it through the bushing hole. Press in the bushing (it will go in snug/tight) and you have your ground wire for a tune-o-matic bridge.

Bootlegger.

 

[jackthehack]

There's debate over bridge grounding???    :icon_scratch: Do some people PREFER hum from the guitar until you touch the strings?

 

[SkuttleFunk]

if I know that I will be playing in a place with two prong (or questionable, or OLD) wiring .... YES

if I am playing a place that is up to reasonably current code, it don't matter

if I am at a recording session, to make the engineer happy I will bring a bass with grounded bridge


what goes out fo my shop depends ...

all the best,

R

 

[Explorerbass]

can someone help me understnd grounding? why do u do it and is it applicable to bass? if so how do u do that?

 

[CD]

Well it takes away the hum that not grounding the pickups causes. I could probably explain more later.

 

[-CB-]

can someone help me understnd grounding? how do u do that?

Usually, I just restrict it to the house with no internet, phone, or TV for a week.

 

[Explorerbass]

lol, seriously cb

 

[Alfang]

can someone help me understnd grounding? why do u do it and is it applicable to bass? if so how do u do that?

Ok Explorerbass, I will give er a go, I have had many classes on grounding, and I understand the hows and whys as good as anyone, just not to sure if I can make anyone else understand what I understand.

The " Ground " in any electrical system is established at the power source, and is done so as to create and equall potential plane amongst all metal conductive parts.  The ground is also connected to the point of return of the circuit, sometimes called the neutral.   So with that in mind, all neutrals and "grounds"  are the place that the electricity wants to go, It's "Home"  it leaves the battery, or generator, and starts looking for home.

In an alternating current system, as the current travels though the wire, it radiates a small amount of energy from that wire out into the surrounding space. Just like an antenna
Once that energy leaves the wire, it's looking for Home, that signal will be absorbed by any metal parts in the area, that are grounded. The higher the frequency, the easier and more electrical energy is radiated outward.

So to prevent all these unwanted signals everywhere, we put a shield arround the wire, Coax Cable, that outter shield does two things, it is the normal return path for the circuit, ie... the signal traveling through the center ultimately returns on the outter shield, and the shield catches those signals jumping off the wire and takes them Home.

In a guitar, the ground is there for the same reason, this is why we install copper shield strips or conductive paint in our controll cavities and arround pickups. Except that in the guitar we are not containing lose signals, we are keeping them out. The pickup is a very sensitive device, it also is an antenna, and can easily hear all the stray signals passing by, so we put up a grounded shield arround the pickups and controlls to absorb that energy and send it home through the ground path, instead of the signal path.

By The way, the ground in your home is there for 1 thing, to make circuit breakers trip. so when something "hot" electrically touches something grounded, the current rush trips your breaker (hopefully)  the ground is not a normal current path.

You know a lot of these big shopping centers and commercial buildings are built with steel studs right? all the metal in any structure is grounded per the national electrical code, so thats why cell phones work poorly inside of a lot of buildings, all those metal studs have created a giant ground shield

Guys I hope this makes sense to someone

 

[Explorerbass]

so, considering the fact that im get active pickups i should ground it? how do u do that?

 

[Alfang]

Your welcome by the way.

Follow the mfg instructions

 

[rahimiiii]

Well, I live in a building with only 2 prongs and I want to create a ground because I don't like getting electrocuted. However I found devices out there (most homes in Taiwan isn't grounded, its 110v with 2 prongs only) that finds the neutral on one of the prongs and hooks ground to that. I can't count the number of times I get shocked by any metal chassis devices here (that includes my computer) so I really need to get this done. However I live on the 7th floor and I can't just stick a 6 foot rod into the ground, so is it okay to hook ground to neutral, am I asking for trouble? As far as I know grounds are connected to the neutral bus in the breakers anyways which is where neutral goes...

I get really crappy cell receptions in my apartment... the building is constructed with steel reinforced concrete.

 

[Alfang]

There's no way to fix your cell service, by grounding anything

You are correct that the neutral is connected to the ground system in the electrical service. IN the USA    I'm not sure how they do wiring in Taiwan.

If you can determine which of the two wires is hot and which is neutral. you COULD in theory, connect all your metal parts in your apartment to the neutral, and connect that same wire to the building steel. I wouldn't try this if I were you... And if that building steel is grounded at the electrical service. your problem would go away.

The reason you are getting shocked is that the neutral in your apartment, which is connected to some of your metal parts, like the metal case of your computer,
The resistance on your neutral, back to the basement of the building where it MIGHT be  grounded is too high.  Follow all that?

So either you have whats refered to as a floating neutral (not grounded ), or you are in contact with something that has less resistance to ground.
The electricity finds it easier to travel through you to get to ground, than through the normal path.  I would bet a paycheck you are being shocked off the neutral.

You need a local electrician to look at it

one more thing, as you move arround your home and touch the water faucet or whatever metal things might be grounded,,,,,your body will act like a capacitor and hold the same electrical charge of the things you touch. and thats normal,,,,then you go touch the computer that is at a different electrical potential and zap!

I am curious if you are sitting there getting zapped all the time, or just once each time you sit down at pc?

 

[Alfang]

rahimiii      I re-read your post and i noticed you said you found a device that could help, IF you can ground it?

Instead of a ground rod, see if you can hook it to building steel, or a copper water pipe-  you might just try an experiment and hook it to the water pipe in your kitchen

Make sure you make all your connections before you plug live electricity into it. hooking it up at one receptacle location might help everything on that SAME circuit.

Let me know how it works  The way to see if its grounded    put one lead of meter on hot wire, the other on water pipe, building steel, sprinkler pipe- if its grounded you will read voltage 115 volts or whatever taiwan uses

Good luck

 

[Erik]

Thanks for the lesson Alfang. I know nothing about electrics, but I know a bit about grounding now, or at least why to do it.
Cheers

 

[Shmoopie]

so, considering the fact that im get active pickups i should ground it? how do u do that?

nope, emgs are all internally grounded  except for the  Hz modle which need to be grounded.
http://emgpickups.com/support.asp

read through the faq, and you will understand how they work a little better.