DCR ,Turns

[copperheadroads]

I have customers inquiring about my pickups reading lower than they should.
& out of spec & so customer returns them & on my multi meter which i own about 5 all read where my pickups should . I don't own a expensive meter the few i own are between $30 to $150 but all my meters basically have the same readings makes me think my reading are correct .
I explain how to measure pickups & correct temp
One know it all customer I have has an $2000 meter at his work & his readings on my pickups are way lower than mine & about 600 ohm lower on a paf style pickup so he thinks my reading & meters are out of wack .
& I'm most of us uses Elektrisola wire 42 poly & PE & winding a paf style pickup with 5150 x2 should end up around 7.8k to 7.9k
Not 7.2k or 5600 turns x2 should be 8.8k to 9k . I wonder what is going on here & why customers are getting the lower readings .

[Jim Darr]

Could be temperature variations/inconsistencies, meter calibration, or range settings.

I really wish people would get away from DC Resistance as an indicator of tone. Sure it has its place and is directional, but people (builders and players) often don't really understand what DC resistance does and doesn't do.

[big_teee]

You need some new customers, not new pickups!

[nickb]

How about you buy a few 1% resistors say 2.2k 4.7k and 10K and use them to check your meter calibration?

[mozz]

If the customer has a expensive LCR meter, he may be measuring them at 120 hz or 1khz.

[salvarsan]

How about you buy a few 1% resistors say 2.2k 4.7k and 10K and use them to check your meter calibration?

Having reference components, even only one, is a good idea.

If you don't mind setting fire to ... (cough!) paying $9 for a single resistor, Mouser stocks Vishay metal film resistors (pdf link) in the .01% tolerance range.
4.57k @ 0.01% means 4570 +/- 0.457 ohms.

[nosaj]

Having reference components, even only one, is a good idea.

If you don't mind setting fire to ... (cough!) paying $9 for a single resistor, Mouser stocks Vishay metal film resistors (pdf link) in the .01% tolerance range.
4.57k @ 0.01% means 4570 +/- 0.457 ohms.

How about this at Electronics Goldmine?
Electronic Goldmine - 3 Piece Precision Calibration Resistor / Set A
Nosaj

[salvarsan]

How about this at Electronics Goldmine?
Electronic Goldmine - 3 Piece Precision Calibration Resistor / Set A
Nosaj

Sure. I suspect that a resistor value near that of pickup coils would be best.
That leaves a lot of wiggle room, I'm guessing 1,000-10,000 ohms.

Nice resource with the Electronic Goldmine site.
Thx.

[jvin248]

.

Are they measuring the pickups in the guitar or on the bench? I seem to get different readings after installing due to some circuit loading.

What signals are in the area; the pickup could be grabbing something creating weak voltages to skew the results too. Guitars on my repair bench seem to pick up noise from the power line outside the house and hum a bit through the amp.

.

[nosaj]

.

Are they measuring the pickups in the guitar or on the bench? I seem to get different readings after installing due to some circuit loading.

What signals are in the area; the pickup could be grabbing something creating weak voltages to skew the results too. Guitars on my repair bench seem to pick up noise from the power line outside the house and hum a bit through the amp.

.

Or buyers remorse.

Nosaj

[jvin248]

Or buyers remorse.

Nosaj

...How expensive are these particular pickups?

[Mick Bailey]

FWIW;

I have a Wavetek and 2xFluke DMMs. Both the Wavetek and one of the Flukes are recently calibrated. I also have some really cheap Chinese DMMS. The readings are pretty close between all of them, except on AC voltage, where the cheapo ones are marginally out (but not a deal-breaker).

The leads me to believe that even a cheap DMM should give fairly accurate readings.

A secondary check for your meter resistance reading is to connect a low-voltage DC supply to your pickup and measure the current as well as the voltage drop across your pickup using a pair of DMMs. Then work out the resistance using Ohm's Law. This should agree with your meter's resistance reading and is sometimes more accurate.

[John Kolbeck]

One know it all customer I have has an $2000 meter at his work & his readings on my pickups are way lower than mine & about 600 ohm lower on a paf style pickup so he thinks my reading & meters are out of wack .

I think mozz is right. Considering the cost, it's probably an LCR meter, which is probably measuring "AC resistance" (not sure how that's distinct from impedance). Ask the customer for the model number of the fancy meter he's using.

[nosaj]

I think mozz is right. Considering the cost, it's probably an LCR meter, which is probably measuring "AC resistance" (not sure how that's distinct from impedance). Ask the customer for the model number of the fancy meter he's using.

Even a $2000 meter can be uncalibrated. How expensive the meter is does not mean it will be correct on readings.Along with asking for the model ask when it was last calibrated. Heck in this day and age have them video them testing it. You might see something they're doing that may not be correct.

nosaj

[Mick Bailey]

I think mozz is right. Considering the cost, it's probably an LCR meter, which is probably measuring "AC resistance" (not sure how that's distinct from impedance). Ask the customer for the model number of the fancy meter he's using.

If he was measuring impedance/AC resistance then his readings would be considerably higher rather than lower, depending on the test frequency.