Gaussmeter Kit Group-Buy

[David Schwab]

I agree. With peak hold off, the numbers jump around too much, and you have to try and spot, and remember the highest number you saw, so you can average them out.

[David King]

Brad,
I think Possum has a point here, knowing the peak reading along a long bar magnet probably isn't all that useful if the reading is way off the map compared to the other readings along the edge. Ideally one could measure the average reading along the whole magnet at once. I do like the peak hold and I wouldn't want to give it up but I don't think it necessarily gives you an accurate picture of a bar every time.

I think taking readings over the poles of an assembled humbucker probably gives you the best idea of how well and evenly magnetized a particular magnet is.

I have only just started to use gauss meter so I don't have a very firm appreciation of what the best method is going to be but I can see right away that a bar ranges wildly along it's length from 150 say to 700 peaks near the corners. I suspect a perfectly magnetized bar would measure about 550 all along the edge...

[RedHouse]

Brad,
I think Possum has a point here, knowing the peak reading along a long bar magnet probably isn't all that useful if the reading is way off the map compared to the other readings along the edge. Ideally one could measure the average reading along the whole magnet at once. I do like the peak hold and I wouldn't want to give it up but I don't think it necessarily gives you an accurate picture of a bar every time.

I think taking readings over the poles of an assembled humbucker probably gives you the best idea of how well and evenly magnetized a particular magnet is.

I have only just started to use gauss meter so I don't have a very firm appreciation of what the best method is going to be but I can see right away that a bar ranges wildly along it's length from 150 say to 700 peaks near the corners. I suspect a perfectly magnetized bar would measure about 550 all along the edge...

I disagree, but to each his own David.

We all have our own ideas on how and what is valuable data to observe and collect and Possum is a man of his own mind and devices. He doesn't see the benefit of this asset.

You do know the readings are not adding up to some "way off the map" value right?, it's simply remembering the last measured highest value for you until you reach another higher number. Remeber all hall effect sensors have a active area of about the size of the point of a pin so readings will fluctuate not average.

You should be interested in finding high spots and knowing them, it can make an otherwise good pickup out of balance.

Look again at the picture above, you can clearly see how to get readings at various segments (the bar pic on the left) you find a spot, go into peak-hold mode and move the probe vertically a couple times and bang, you're done there, then move down to another spot along the length and repeat, do this 3 or 4 times and you have a decent profile of the magnet and it's peak output at any given place (you chose).

Why not average? well for example I have the A5 bar here in front of me right now that Wolfe charged on his charger and gave me. This particular A5 bar has 810-G/peak at one end, 650-G/peak in the middle, and 890-G/peak at the other end. I'm talking about the 1/2" ends not the 1/8" edges here.
(I marked the places with a ultrafine sharpie for future reference)

So installing this magnet one way can favor the low-E with that 890-G or if you flip it (maintaining N/S polarity) it can favor the high-E with the 890-G. While the D and G string poles are always known to be 150-G less on this magnet. Why would one want to know an "average" down the length of this magnet and ignore the huge variance from end-to-end, and in the middle? I suppose one could just raise the D and G poles up higher toward the string to balance the pickup out more but that would make it look weird. Further consider that magnet in relation to this next one, another A5 sand cast bar I have here (from a BurstBucker) which varies less than 30-G/peak measured in the same 3 places down it's length again getting the peak off it's 1/8" edges. If you had these two magnets to build 1 decent pickup out of, would you choose based on an average reading? not likely.

I do agree with you about measuring poles after pickup assembly but for evaluation of complete pickups and their relationship to other pickups, not so much for charging or selecting charged magnets for one's best pickup builds.

Fluctuating readings are the way it is, regardless of peak-hold or normal mode, an Elepro or AlphaLab meter. I just don't see the "way out there, off the map" point that you and Possum are on about.

Is it anything to do with those black helicopters you were talking about?

[mkat]

I finished assembling the gaussmeter last night and took some readings, very happy . I left the sensor flat also and wired in the cap near the sensor (using a cable around 14mm in length) and used a microphone connector to attach the probe to the unit. Thanks a heap guys.

[-Elepro-]

The sensor's active area is very small, like the point of a pin so you have to move it around to find the max gauss reading, that is why the "Ph" mode is so useful without it you have to look at the display and try to remember the highest reading you saw as you moved the probe around.

I'm not so sure using peak hold on your guassmeter when measuring a bucker magnet is such a great idea. If your probe wanders along the edge of the pole side it'll read higher than whats coming off the face. I think its better to slide it along and watch the numbers in real time.

This meter just holds the highest reading it encounters until the probe is removed from the magnetic field.

Peak-hold eliminates some opportunities for error in other meters (both user and device) for instance:

• you may blink right when it reads a highest reading, or forget what it was if distracted
• you may look away from the display to make sure you have the probe correctly on the magnet and miss a higher reading than you remember
• the probe may hit a high spot in-between samples the meter takes
• the probe may hit a high spot in-between when the data was flushed to the LCD screen.

The peak-hold mode just remembers the highest reading for you at 64 samples per display update which appears to my naked eye to be around 4-6Hz (1024 samples in "Nm" mode). Much more samples and much faster than many other units.

I think that for perfect valuation of a magnet it's better to use both method (if your gauss meter can make both)

Ideally one could measure the average reading along the whole magnet at once.

yes.... i could add an average mode too.. it operation could be:

- put probe near magnet and start average mode and start probe movement along magnet
- after 3-5 seconds display show an average of about a thousand of readings (each one taken with 1024 samples)

what about this???

[RedHouse]

... yes.... i could add an average mode too.. it operation could be:

- put probe near magnet and start average mode and start probe movement along magnet
- after 3-5 seconds display show an average of about a thousand of readings (each one taken with 1024 samples)

what about this???

Sure, but how would we all get the firmware upgrade?

[-Elepro-]

not upgrade... only in future gaussmeter.....

[David Schwab]

not upgrade... only in future gaussmeter.....

See... You should have had the Gauss meter internet ready!

But thank you again for the very cool design, and for sharing it with us here.

[RedHouse]

not upgrade... only in future gaussmeter.....

Speaking of that, check you email.

...But thank you again for the very cool design, and for sharing it with us here.

Yes, thanks from me also Elepro.

[Joe Gwinn]

not upgrade... only in future gaussmeter.....

Would it need more than a new PIC?


In addition to an averaging mode, what would be useful would be a way to measure magnetic potential, just as done using Chattock and Rogowski Coils.

US Patent 4,625,166 to Steingroever shows how to do this with multiple hall probes, but one could use one moving hall probe and a computer instead.

[Jeff Callahan]

Help with Gaussmeter Kit

I've finally found someone to assemble the kit (not trusting my experience in electronics), and he told me the chip was not programmed. It seems like everyone got theirs to work fine, so I have a few questions...

He told me that the thing powers up fine, but the screen only shows blocks in the first line, and nothing in the second. He seems to think the chip is not programmed. I'm pretty sure this is not the case, but any information would be appreciated.

If the PIC is defective, is their any way to get another, and if so how much?

I haven't seen the assembly, but he is more than qualified, so I'm not sure what to do next?

Thanks, Jeff

[RedHouse]

I've finally found someone to assemble the kit (not trusting my experience in electronics), and he told me the chip was not programmed. It seems like everyone got theirs to work fine, so I have a few questions...

He told me that the thing powers up fine, but the screen only shows blocks in the first line, and nothing in the second. He seems to think the chip is not programmed. I'm pretty sure this is not the case, but any information would be appreciated.

If the PIC is defective, is their any way to get another, and if so how much?

I haven't seen the assembly, but he is more than qualified, so I'm not sure what to do next?

Thanks, Jeff

You will have to address Elepro for that question, he asured us that he programmed and tested every PIC he shipped to us.

Perhaps you can get your friend to post his problem here and maybe it can be helped with.

[David Schwab]

but the screen only shows blocks in the first line, and nothing in the second.

Did he adjust the contrast trim pot?

[-Elepro-]

yes i tested all PICs with a gaussmeter built just for this test.... (you can see it in a photo in the previous page of this thread).... just for not have this problems!!

then: or an esd burned your pic, or it went in the socket on the wrong side.....


say to your friend that screen shows blocks in the first line and nothing in the second when LCD is not initialized, this occurs also when pic is burnt .....

why he said it is unprogrammed and not burnt???




please post some photo of your pcb on both side....

however.... Redhouse have a 1+ pic that i sent him as spare part....


ciao

[RedHouse]

...however.... Redhouse have a 1+ pic that i sent him as spare part....

No spare parts, realtonecustompickup got the "extra" one so it's back to you to support your PIC's.