what is involved in alnico recharge?

[joe3rp]

I had my 515B woofer reconed and alnico-recharged by GPA recently - 1st class operation/workmanship.

What is involved in the re-mag process? GPA charges a really minimal fee for the service. The biggest problem is the size/weight/cost of shipping to send stuff to GPA and back!

Is the re-mag machine a large and "lethal" device ? Is there a machine like this available for sale or for DIY?

Can you only re-magnetize ALNICO?

[gearjammer]

If you were to buy one it would cost you a small fortune. Also any type of magnet can be charged up alnico or ceramic or any other type. I suppose in the wrong hands it could be lethal as well. the one at great plains runs on 240v and I have seen things shoot across the room when the machine is in operation, like rasor blades and paper clips!!!!!

[Altec19]

Here is a photo of the magnetizer at GPA. The capacitor bank is behind the chair and the coil is on the bench. The whole process from placement to discharge only takes a couple of minutes. They have to place some shims in the bottom of the coil cavity to align the central horizontal plane of the coil with the horizontal plane of the driver magnet. If those aren't pretty close to aligned the driver might launch. A person sort of cradles and lays across the top of the woofers during the actual discharge to hold it down (just in case). It takes maybe 15 seconds for the capacitor bank to charge and just a fraction of a second to discharge into the coil.

Link to GPA Magnetizer

[joe3rp]

WOW! to both comments. Is this the same machine used for the tweeter/midrange magnet drivers? So the hole is where there place the magnets?

CAPACITIVE DISCHARGE MAGNETIZER...what is the Brand Name? Maker?

If a person has to hold down the magnet, he will be in very close proximity, he should not have any metal-magnetic stuff on him.

[Altec19]

WOW! to both comments. Is this the same machine used for the tweeter/midrange magnet drivers?

I believe so.

So the hole is where there place the magnets?

Yes.

CAPACITIVE DISCHARGE MAGNETIZER...what is the Brand Name? Maker?

I don't know. The label on the front panel actually says "Capacitor Discharge Magnetizer". I did a Google search and came up with several vendors.

If a person has to hold down the magnet, he will be in very close proximity, he should not have any metal-magnetic stuff on him.

Correct.