A3 Rod Magnet Pickups

[big_teee]

Does anyone here make A3 Strat or Tele Pickups?
Curious what kind of gauss reading to expect on fully Charged A3 Rod Magnets?
Not to be confused with A3 Bar Magnets!
Thanks,
T

[David King]

I have some unmagnetized A3 rods I can charge up and check if that would help. What length are you using? I have .630 and .850" so we may have to extrapolate. I made a bass pickup with them and didn't care much for it at the time. Tom Jones had just been telling me how much he liked A3 and I figured it would be worth a shot.

One odd thing I noticed recently with A2 is that it takes a bit more coercive force to get them fully charged than it takes for A5s. Not at all what i would have expected. A3s may also require a bigger charge bump even though they are the weakest of the pack.

[big_teee]

I have some unmagnetized A3 rods I can charge up and check if that would help. What length are you using? I have .630 and .850" so we may have to extrapolate. I made a bass pickup with them and didn't care much for it at the time. Tom Jones had just been telling me how much he liked A3 and I figured it would be worth a shot.

One odd thing I noticed recently with A2 is that it takes a bit more coercive force to get them fully charged than it takes for A5s. Not at all what i would have expected. A3s may also require a bigger charge bump even though they are the weakest of the pack.

I agree it seems harder to get the weaker mags charged.
I put some A3 in a tele and they sounded great, they didn't get checked.
They really had a sweet tone in the bridge.
A friend of mine was wondering if he could get 900 gauss with his strat length A3s.
I told him that seemed a bit hot.
Sure, if you don't mind, check the .630s and and the 850s.
Thanks,
T

[Lyrebird Steve]

my A3's come in pre-charged at 477.

The ones I have re-charged with Neos I've pushed up to 495 - 497(.630 & .710)

I think 700 might be tough

[kayakerca]

my A3's come in pre-charged at 477.

The ones I have re-charged with Neos I've pushed up to 495 - 497(.630 & .710)

I think 700 might be tough

For those that dislike my anal approach to things. . . Don't look!

OK, here we go from the non-tech newbie hobbyist. . .

My understanding is that A3's are typically isotropic (un-oriented) compared with A5's which are typically anisotropic (oriented). So what I would take from that is that you are more likely to have the orientation axis of the charge change if you charge your A3's by using the slide the magnets through a vice type approach vs. moving the charging magnets directly (squarely) in and out for the Alnico being charged.

Is this possible? Well I did a test. I took two A3's - .195" X .710" and charged them 2 different ways.

Way #1:

I slide the A3 between 2 - 3" N42's in a small vice. In one side, along the face of the N42's and out the far side a couple of times. The only spacer was a piece of teflon sheeting on either side of the A3 to let it move through a little easier. Here is the resulting charge on the A3. The charge settled in at about 490 mT.



Way #2:

I used used my charging setup of 2 - 3" N42's and moved the charging magnets in and out a couple of times staying absolutely perpendicular to the A3. The A3 was spaced ~ 3/16" from the N42 charging magnets, being the thickness of the plastic rigging that holds the 3" - N42's. Here is the resulting charge on the A3. The charge settled in at about 626 mT. I'm guessing that if I had no spacers between the pair of N42's and the A3, I'd probably get pretty darn close to a full charge potential of 700 mT.



What this anal newbie hobbyist takes away from this test, rightly or wrongly, is that you could well have a difficult time fully charging an un-oriented A3 if you are charging with the slide in/slide out of a vice type technique as when you exit the vice area the orientation of the charge changes directional off the long axis in the A3 (and weakens). If you use the straight in/straight out technique with a pair of large N42's, you probably can, if that's what you are looking for.

Have at it. . .

[big_teee]

To start with what is mt, is that micro or milli tesla?
Would be nice if we stuch to standard Gauss?

[kayakerca]

To start with what is mt, is that micro or milli tesla?
Would be nice if we stuch to standard Gauss?

You're welcome. . .

[big_teee]

You'e welcome. . .

Thank You!
I'm still trying to process, and come up with what gauss you got.
The mt doesn't off hand ring any bells, or whistles.

[kayakerca]

Thank You!
I'm still trying to process, and come up with what gauss you got.
The mt doesn't off hand ring any bells, or whistles.

gauss = mT X 10

Both my meters measure as mT. Here is a Alnico table where you can see both.



Hope that helps a bit.

[big_teee]

Yes the chart really does help.
So looks like everyone around here is in error when they say 600 gauss, when actually it is 6000 gauss.
So Thanks for clearing that up.
That's what I was trying to wrap my head around!
It looks like the readings you get are right in line with the chart.
Thank You,
T

[David King]

I've resorted to charging my rods one by one in the pickup by using a long stack of 3/8" x 1/8" neo discs on the top and bottom. I let the neo stacks slam into the rods a few times and pull them straight off. You can feel the pull getting stronger and stronger up to 3 or 4 cycles. After that it stabilizes but I don't know if they're actually saturated or not.

Using the peak hold function on my mkII elepro and scanning each end, all around the edges I'm getting 855 G off the ends of the .630" A3. W/o peak hold and sampling the center of the rod I get a reading of 733.

On the .850" long rod I get a peak hold reading of 1085 G and a non peak hold center reading of 940 G.

I got the .630 rods from Addiction FX, the .850"s came from Sensmag.

[kayakerca]

Yes the chart really does help.
So looks like everyone around here is in error when they say 600 gauss, when actually it is 6000 gauss.
So Thanks for clearing that up.
That's what I was trying to wrap my head around!
It looks like the readings you get are right in line with the chart.
Thank You,
T

I had been meaning to do that charging experiment for a while now but never got around to it. Your thread here prompted me to actually get at it. I've seen numerous posts (possibly here or elsewhere, I can't remember exactly) talking about whether or not the the various ways of charging Alnico's affects the final charge strength and/or charge orientation.

[big_teee]

I've resorted to charging my rods one by one in the pickup by using a long stack of neo discs on the top and bottom. I let the neo stacks slam into the rods a few times and pull them straight off. You can feel the pull getting stronger and stronger as to 3 or 4 cycles.

Using the peak hold function on my mkII elepro and scanning each end all around the edges I'm getting 855 G off the ends of the .630" A3. W/o peak hold and sampling the center of the rod I get a reading of 733.

On the .850" long rod I get a peak hold reading of 1085 G and a non peak hold center reading of 940 G.

That is a hot reading.
I suspect if you let them settle for a while, you would get quite a bit less.
T

[David King]

That's good to know Terry, I'll check them again later on.
Here's a converter web app. Convert Magnetic field
In Jim's table above it doesn't specify what the sample size is so I'm not sure how I would use that other than as a rough guide.