Do any of you electronics gurus have a process where you test all electronics (pickups, volume pots, switches, etc.) prior to beginning assembly to ensure everything is in good working order?
Printable View
Do any of you electronics gurus have a process where you test all electronics (pickups, volume pots, switches, etc.) prior to beginning assembly to ensure everything is in good working order?
I do...
Mostly with an ohms meter. I check the pickups to make sure that each coil gives a resistance reading that it should. I test all the pots to make sure that the total resistance is right. I also check them at "5" to confirm that the taper is audio or linear (I don't trust what is stamped on the case or wafer) and that they all show about the same reading at "5." Since pots of, say 500K, can vary by over 100K, I also check to see that they are at least close to each other. I don't usually do this with new pots, but I have occasionally run a signal through them and listened for scratchiness.
I test all the switches to make sure they are working properly with the ohms meter. In this case I am just testing for continuity...that connections are open or closed as they are supposed to be (1=not conneted, ~0= continuity).
If I use any simple resistors, I test them. I did not used to have a meter that would test caps, but I do now, so I test them as well. I admit that I do this not so much to see if the resister is faulty, but more to make sure I have the right one ;-)
Once everything is connected, I clip a lead onto the ring of the jack and test to see that all the pots, switches, shielding and the strings show as continuous.
On my last project and on the one I am working on now, I have assembled the wiring harness on a template. Once the pickups are installed, I can test the wiring harness before putting it in the bass. This was VERY useful on the last project, an ES style bass. On these you have to shove the whole wiring harness through the f-hole, so you want to get it right. As I was testing the tone control, I realized they were basically not rolling off any treble. I got some advice from Weirdbits about changing my cap values, and was able to do that before putting the harness in the bass. Also, while I was testing on that bass, I pulled the shaft out of one of the pots...and was happy to have that happen during testing rather than when in the bass!
I am testing paint and finishes right now... The more experience I get the more I test everything I can.
Not much I could add to what fender3x said other than I could not live without my Digital Multi-Meter (DMM for short).
A multi will give you resistance, capacitance, voltage, continuity etc. Mine will even do temperature with the special probe.
I use it constantly for all sorts of guitar work. Mine has an audible alarm for continuity testing which I find very handy.
A decent one is not that expensive (especially if you consider how much we all spend on guitars/pedals/amps :D) and having one is simply invaluable.
My multimeter is not as fancy as McCreed's. The "fancy" one cost me less than $20. It will measure inductance (which is useful for pickups), capacitance and resistance. That's all you need for what I wrote above. Search for a multimeter with the model name "4070L." Cheapest one I could find that measures capacitance. They are marketed under different brands (read that cheap Chinese)...interestingly all with the same model number. I have also seen 4070D...don't know what the difference is, but mine has worked impressively well.
I also have a few really cheap ones (I don't think I have ever paid much more than $10). These won't measure capacitance or inductance, but work just fine for resistance and testing continuity. Also they are great for testing batteries and LOW voltage. Don't use one of these on any real voltage!
I don't know how people lived before these devices were cheap and plentiful ;-)
f3x,Quote:
Originally Posted by fender3x
Thank you for your detailed response! Very helpful. I have a good multi-meter (see attached) that I can use to run the tests you mention. I'll give it a try and post other questions here if I get stuck.
Rick
Attachment 31571
Thanks McCreed. My DMM tests continuity with an alarm as well. It does the rest of the tests too. I'm going to dig in and learn as much as I can on how to run the tests you gents recommend. Appreciate your input!Quote:
Originally Posted by McCreed
Rick
Looks like I need the 4070L you recommend to test inductance in order to test the pickups. Thanks again f3x!Quote:
Originally Posted by fender3x
Based on the photo you posted, it doesn't have continuity or inductance capabilities.
Also, I've never seen a "cheap" DMM that can measure inductance. The only devices I know of that will measure inductance (L) are an oscilloscope and signal generator.
My understanding is (and it is a tentative grasp at best) that a typical DMM does not have the capacity to generate appropriate signal frequencies as part of the L measuring process and are expensive bits of kit to make.
McCreed, according to my DMM manual a continuity test can be performed, see first attachment. It cannot perform inductance tests but the 4070L advertises it does per the second attachment (note that it tests for H not L.) I agree that an oscilloscope and signal generator are optimum -- but out of the question for me really.Quote:
Originally Posted by McCreed
Maybe the 4070L DMM does not give a fully accurate reading or like you say, won't achieve appropriate signal frequency. To be honest, I doubt I would get that advanced in my testing. I guess I'm looking for simple tests that I can perform to avoid problems before I install the electronics and also a means to learn more about guitar electronics theory.
Curiosity killed that kitty, so I've got to watch my paws. :cool:
Thanks for following up, my friend.
Rick
Attachment 31572
Attachment 31573
Looks to me that the 4070L DMM is all you need for doing what most of us do here.
I can't attest to the inductance, but I'd be sceptical. The other functions are more important for guitar wiring work IMO.
And just to clarify - "L" means inductance; and inductance is measured in units called Henrys (H).
I have only used the inductance function to see if my pickups' specs were what the mfg said they should be. Of course the only pups I have that *tell* me what the inductance specs should be are my Bill Lawrence's. One and only to e I used that function. My wife is convinced that that is enough and that we don't need an oscilloscope.
I haven't a clue as to how accurate the inductance reading is on the 4070...It was very close to what BL said my pups should be...
I use the Ohm meter by far the most. I use the cap meter some...and that's pretty much it, so to me the Craftsman does pretty much all you'll need to build a guitar.
I don't think I know enough to endorse the 4070. I just put it out there as the cheapest one I have found that can measure caps.
BTW the 4070D seems to have identical functions to the L. Both are listed as RCL meters. I thought the "L" might stand for "light" since it has s backlit screen...but the D seems to have this feature too. My current theory is that D stands for "discontinued" since only the L model is listed on the mfg's website ;-)
Sent from my ONEPLUS A3000 using Tapatalk
I see. You've given some very good pointers f3x but a lot flies over my befuddled newbie brain. Do you know of a resource that gives me step guidance (with lots of those 1000-word images) that will get me started with understanding my guitar electronics and initial tests? I am reading guidance on this forum and watching videos but things are spread out. It doesn't help that I have limited knowledge that inhibits my online searches. If you know of a forum post or other online reference that would help, please send my way. Meanwhile, I'm still studying.Quote:
Originally Posted by fender3x
You mention assembling "the wiring harness on a template." I have a breadboard and electronic connectors. Do you know a resource that illustrate how to setup a template for more accurate testing?
I'm throwing a lot at you and McCreed but you fellas have a wealth of knowledge.
Happy 4th of July from an old Yank.
Attachment 31574
I liked the graphic ;-)
Here's a tutorial on testing with a multimeter...
https://www.youtube.com/watch?v=Tr-8uj95330
Your wiring is simpler than what is depicted in the video, but the principles are all the same.
I would note that he tests continuity on the backs of the pots. That should be fine, but I generally do it on the ring of the jack. It shouldn't matter too much, but I do it at the jack because that's where the ground ultimately has to be. Once it is all installed, clip one lead to the strings and touch the ring of the jack to make sure they are grounded as well. You can do the same with the shielding if you add some.
I use a template like the one the guy uses in the video...all that means is that everything is arranged on a piece of thin wood or cardboard that has been drilled to be exactly like where the controls will go. That's important on my project, which is an ES. You already have a built in template, since your switch and pots all fit on a Tele control plate.
Did your kit come pre-wired? I have not seen one of these kits. The pics on the website don't show the back of the control plate. If it's prewired, then great! If not you'll need a wiring diagram. Caution, do not use the one on the Pitbull website because it's incomplete. Additional caution, there are at least two common types of Tele switch and they are wired a little differently. A pic of the back of your control plate would clear this up (for me, anyway...others may already know) ;-)
You can test the pups as in these videos. Your pickups should only have two leads, so you probably don't need to see much more than half the video ;-)
https://www.youtube.com/watch?v=kK-yUVlBltU
https://www.youtube.com/watch?v=tMaRs1jGQPg
I am guessing that they will have resistance in the 3-5K range. A little higher for the bridge than the neck.
Hope this helps!
The links are amazing, just what I needed f3x! You be THE MAN!Quote:
Originally Posted by fender3x
I'll check into that and probably have some questions for you.Quote:
I would note that he tests continuity on the backs of the pots. That should be fine, but I generally do it on the ring of the jack. It shouldn't matter too much, but I do it at the jack because that's where the ground ultimately has to be. Once it is all installed, clip one lead to the strings and touch the ring of the jack to make sure they are grounded as well. You can do the same with the shielding if you add some.
Based on what I saw in the videos you shared, I'm thinking I can lay out the control panel, pickups and output jack, clipping the connections to the pickups and output temporarily as long as I get the earth (ground) connections right. Then I can run an end to end test on everything, in addition to individual tests on the other components as shown in vids.Quote:
I use a template like the one the guy uses in the video...all that means is that everything is arranged on a piece of thin wood or cardboard that has been drilled to be exactly like where the controls will go. That's important on my project, which is an ES. You already have a built in template, since your switch and pots all fit on a Tele control plate.
Did your kit come pre-wired? I have not seen one of these kits.
The switch and pots in the control plate are pre-wired. I must wire to the pickups, output jack and ground under the bridge. See these quick pics:
Attachment 31578
Attachment 31579
The blue wire connected to the pot above looks a bit messy. I found an errant wire stringing out. I will clip it back so there is no electronic interference.
Attachment 31580
Attachment 31582
On the Tone pot seen above, notice that the capicitor wire connected to the pot (not ground on top) sticks out visibly. Do you think I should trim that back as well or is it acceptable sticking out like that? Printed on the capcitor is 2A473J. No data besides CE is printed on the back of the volume and tone pots and nothing on the switch circuit board. I'm going to do some research on the pots, switch and pickups to see what I can find so far as specs. It's that old kitty curiosity kicking in. :cool:
I agree, the pic on the PBG site is confusing, but I figured it out. I also watched the PBG TL-1 wiring video at https://youtu.be/pj3NLscxD0U so I think soldering to and installing the control panel and pickups will be pretty straightforward.Quote:
The pics on the website don't show the back of the control plate. If it's prewired, then great! If not you'll need a wiring diagram. Caution, do not use the one on the Pitbull website because it's incomplete. Additional caution, there are at least two common types of Tele switch and they are wired a little differently. A pic of the back of your control plate would clear this up (for me, anyway...others may already know) ;-)
This helps immensely, my friend. Just what I needed. Thanks so much!Quote:
You can test the pups as in these videos. Your pickups should only have two leads, so you probably don't need to see much more than half the video ;-)
...
I am guessing that they will have resistance in the 3-5K range. A little higher for the bridge than the neck.
Hope this helps!
Rick
I'd trim any wire that just sticks out, like the one on the cap. As long as it doesn't touch anything that's not already grounded it shouldn't matter either way. I'd just do it to keep it from catching on anything.
Sent from my ONEPLUS A3000 using Tapatalk