Pickup with uneven string response

[Biarnel]

Just a quick (I hope) question:
Why in a (supposedly!) well wound coil a string would sound weaker than the others?
I have a bass PU with a very low volume D string.
I used one 10mm dia. alnico rod per string: maybe that rod is a lame magnet? Demagnetized somehow?

If this is the reason, how should I prevent this from happening?

[Possum]

magnet....

Magnets are not all the same, sometimes there will be a magnet that won't hold as high a charge as the same in a batch from the factory. You could try recharging the magnets and see if that helps.

[Biarnel]

The problem is: how may I spot a weak magnet before the test drive of the finished pickup?
I may recharge the mags with the rare earth magnetizer form stew mac, but.. how much? Recharging "by eye" will lead to different streght, won't it?

A question for you heavy duty winders: what is your workaround for weak magnets?

[gilligan]

The low volume string magnet could be upside down also. Three north up, and one south up, will also cause that.
Ron

[Possum]

gaussmeter

There's no way around it you will need a guassmeter to correctly identify a weak magnet and magnets that won't hold a good charge (which is somehwat unusual but I do find some now and then). No you can't really charge your magnets very good with StewMac's magnets, they aren't really strong enough to do a full charge. If you look on Ebay you can find alot of neo magnets, you need something fairly sizeable really, like a block that is 1/2 inch thick and 2 inches square. With these you can charge alnico from one side only instead of trying to charge from two sides. There are some websites that show how to make a gaussmeter from Radio Shack supplies but some of these won't read very strong magnets like alnico. I have seen a guy on Ebay who sells a gaussmeter made for model race car hobbyists, but I'm not sure if he is still making them or not, they were about $100 and would work. You need something that will read up to about 1500 gauss minimum. A fully charged strat magnet can hit 1200 gauss easily.

[nhall]

Gauss Meter

Yes ...the ebay guy is still making them......I bought one from him only a month or so back, and its very neat (for a small work space) and reads nice and clear...for me it works well, and has confirmed a few outstanding queries I had regarding what was happening in some single coils I had..!!
I think I will still have the Ebay ref. in my ebay history if you need it....I contacted the guy via an old ebay link, but he still insisted in listing the inem for me to buy it because he didn't want to upset ebay in case they found out he sold off line also!!!!
Anyway you have to ask him for the upgraded version to be able to measure stronger gauss magnets...he does a simple one strength version aimed at the model racer motor builders, and then one with an added level of measurement ability..