Help with ohm reading

[djwackfriz]

OK, I read all 11 pages of posts when I searched for "test ohm", and nothing has given me the info I need, or at least in a way that my feeble mind can understand it. Please help me.

I recently switched the pickups in 2 of my basses, drew diagrams before soldering, matched everything perfectly. The problem is, I'm not wholly confident in my soldering skills yet, and I want to test whether everything is connected correctly, or if I have any cold joints.

My multimeter readings are as follows:
Neck pickup:
off = 0.0
all the way on: 5.31
Bridge pickup:
off: 0.0
all the way on: 5.25
both pickups on: 2.7 for both

First, do these numbers look consistent/good? Are there more readings I can do? I'm anxious to learn more about this, it's actually pretty fun!

Thanks for any help

 

[paullong444]

If you don't hear any problems when the bass is plugged in then there shouldn't be a problem with you solders.

 

[djwackfriz]

If you don't hear any problems when the bass is plugged in then there shouldn't be a problem with you solders.

OK cool, so a cold joint won't affect the output of the bass? In other words, they either work or they don't?

 

[A9X]

OK cool, so a cold joint won't affect the output of the bass? In other words, they either work or they don't?

A cold joint may not make itself known for a while. I'd be more concerned with neatness of wiring, ie no loose strands anywhere and shiny looking solder joints. A DMM won't test for a cold or otherwise imperfect joint unless it's completely open. Just plug the bass in; if something is miswired it won't work correctly but you won't damage anything.

 

[luknfur]

FWIW:

as has been mentioned, if it sounds good it is good and if the solder points are chrome looking there's little concern. I wouldn't get hung up on the chrome look cause at least a cold joint won't damage anything, overheating can. If you're getting a blue tint to chrome looking joints then probably too much heat. If the solder points are dull looking then there may be an issue in time or there may not. If they look like welding slag then some practice with soldering is indicated.

If use a good acid free solder around 70/30 mix, heat both surfaces using a 15/20 watt gun, you should be find. There's a soldering thread in FAQ.

 

[djwackfriz]

Thanks for the info folks, I appreciate it.

For future reference, what exactly am I looking for when testing resistance? Where do I get my numbers from? How do I know if the result is good/bad?

 

[A9X]

Thanks for the info folks, I appreciate it.

For future reference, what exactly am I looking for when testing resistance? Where do I get my numbers from? How do I know if the result is good/bad?

Depends what you're trying to measure. But I don't ever use the numbers for a pickup with the pot in circuit. Measure it before soldering in. If OK, then as you saw, the pots will affect the readings as they're part of the circuit too, so then do the variations go in the way I expect? If so, it's OK.

The readings you gave in the first post are about what I'd expect for a J bass, in terms or numbers and trend.

 

[luknfur]

Thanks for the info folks, I appreciate it.

For future reference, what exactly am I looking for when testing resistance? Where do I get my numbers from? How do I know if the result is good/bad?

The pup has to be disconnected to measure DCR. Most manufacturers list specs for a comparison. In general for passives expect between 7K to 11K for 90% of them but todays pups are actually very consistent so it should be practically dead on to a manufacturer spec. Active pups will usually be around 2-4K.

For grounding you're looking for infinity reading - no resistance.

Meters come with instructions/explanations too.