Unstable Micro Ohms

[Kemosabe]

ive made dozens of micro coils. all of them work amazingly..until now. i recoiled my octo and my phoenix with cotton micros. they metered out fine when first built, but now that theyre wicked and wet, the resistance is bouncing as if i had a loose connection on one of the posts. but the screws are secure as hell. they are tightened down to the max. it does not appear that the coil is touching any metal, like the top cap for instance, that it would short on. i am perplexed.

perhaps the positive pin isnt stable. that is the only thing i can think of. but for the same weird problem to be happening on both attys is whats confusing me. the 510 area of the pos pin on the phoenix is tilted ever so slightly, could that be giving me my bouncing resistance? but with the octo the pos pin looks and feels stable as hell. any help would be appreciated.

 

[State O' Flux]

Same lot of wire you've been using... or new roll?

Confirm variance with a different ohm meter... or DMM?

 

[Kemosabe]

Same lot of wire you've been using... or new roll?

Confirm variance with a different ohm meter... or DMM?

same lot of wire. its from Temco. 28g. toward the end of the spool at this point if that makes a difference.

a have problem with using another form of checking ohms (i trust the provari for this more than i trust anything else i have). the DMM is never accurate. perhaps im using it wrong, perhaps its the fact that its the $5 one from Harbor Freight. i tend to think im using it wrong because the voltage checking option works flawlessly.

but when it comes to checking resistance, it appears to be way off. heres what i do: i select the "200" from the resistance category and see that my lead resistance is 1. i then attach alligator clips to the ends of the leads for ease of gripping my pos and neg posts. then i read the resistance. holy crap i just realized from typing that all out that my alligator leads are probably adding another ohm of resistance.(!) guess i gotta re-do my tests. d'oh! well hey, at least im getting somewhere lol. question: is there any way to tell the combined resistance of the leads + the alligator clip leads? in other words, will the DMM show me a "2" for example instead of the "1" from the regular leads' resistance..because im fairly certain the DMM still just said "1" before i tested the coil. if it were a "2" i might have noticed rigth away and not have had to type this whole thing out lol.

my other way of checking resistance is an ohm-checker box. its the rechargable one made by tobeco i beleive. this box is handy as heck, but it doesnt do the "ohm bouncing" that the provari does. it just picks a resistance and sticks with it. is the provari reading TOO accurately, signifying a problem when there is none? or is the ohm box not reading accurately enough? confusing. but maybe i wont even need to know seeign how the DMM is likely the most accurate- IF i can determine my total leads' resistance, that is.

 

[State O' Flux]

same lot of wire. its from Temco. 28g. toward the end of the spool at this point if that makes a difference.

a have problem with using another form of checking ohms (i trust the provari for this more than i trust anything else i have). the DMM is never accurate. perhaps im using it wrong, perhaps its the fact that its the $5 one from Harbor Freight. i tend to think im using it wrong because the voltage checking option works flawlessly.

but when it comes to checking resistance, it appears to be way off. heres what i do: i select the "200" from the resistance category and see that my lead resistance is 1. i then attach alligator clips to the ends of the leads for ease of gripping my pos and neg posts. then i read the resistance. holy crap i just realized from typing that all out that my alligator leads are probably adding another ohm of resistance.(!) guess i gotta re-do my tests. d'oh! well hey, at least im getting somewhere lol. question: is there any way to tell the combined resistance of the leads + the alligator clip leads? in other words, will the DMM show me a "2" for example instead of the "1" from the regular leads' resistance..because im fairly certain the DMM still just said "1" before i tested the coil. if it were a "2" i might have noticed rigth away and not have had to type this whole thing out lol.

my other way of checking resistance is an ohm-checker box. its the rechargable one made by tobeco i beleive. this box is handy as heck, but it doesnt do the "ohm bouncing" that the provari does. it just picks a resistance and sticks with it. is the provari reading TOO accurately, signifying a problem when there is none? or is the ohm box not reading accurately enough? confusing. but maybe i wont even need to know seeign how the DMM is likely the most accurate- IF i can determine my total leads' resistance, that is.

$5 at HB huh? Big spender. Might want to drop $25-$30 for something a bit better, like with auto ranging. Or you could get a Fluke 88 and be king (or at least a duke) of the DMM guys. ;-)

Attach all your test lead stuff... and touch the leads to each other. Allow to stabilize and read internal resistance. Subtract that value from measured resistance of atty atty or coil.

 

[Kemosabe]

$5 at HB huh? Big spender. Might want to drop $25-$30 for something a bit better, like with auto ranging. Or you could get a Fluke 88 and be king (or at least a duke) of the DMM guys. ;-)

Attach all your test lead stuff... and touch the leads to each other. Allow to stabilize and read internal resistance. Subtract that value from measured resistance of atty atty or coil.

HUGE spender LOL
as a matter of fact i didnt pay anything for the meter. its normally $5 but i got it free with a coupon, barring i made another purchase (which was the alligator clips, which i already wanted anyway). so in my mind i was king of HF (at least for that day anyway).

thanks for the help. what does auto-ranging do?

 

[State O' Flux]

HUGE spender LOL
as a matter of fact i didnt pay anything for the meter. its normally $5 but i got it free with a coupon, barring i made another purchase (which was the alligator clips, which i already wanted anyway). so in my mind i was king of HF (at least for that day anyway).

thanks for the help. what does auto-ranging do?

Oh... you're one of them cheap bastadges that got in on that deal before HB went "duh... we got problems boss" and shut it down.
Seriously... I wouldn't trust one of those to read low resistance, as far as I could toss it in a trash compactor. Your Provari is light-years ahead of it for accuracy and consistency.

I've had the same Fluke 88 for... maybe a few decades now. Back then, a 88VA kit (right after they upgraded to a 30a "fast test" capability) was $250, not the $550-$650 they are now.
Actually, I've seen 88-5s with no extras for under $400 on eBay. Genuine Fluke accessories will kill ya'. ;-)

Crap... forgot. Auto ranging will read resistance, and select the appropriate scale for you. Handy huh?

 

[Uma]

Whenever mine went wacky, it was because moisture was inside the positive post tube connection thingie. When it's dry as a bone, the readings are stable.

 

[Kemosabe]

thanks for the tips. yup, im one of those cheap bastages. i kinda have to be seeing how i dont have a whole lot of discretionary income.

Oh... you're one of them cheap bastadges that got in on that deal before HB went "duh... we got problems boss" and shut it down.
Seriously... I wouldn't trust one of those to read low resistance, as far as I could toss it in a trash compactor. Your Provari is light-years ahead of it for accuracy and consistency.

I've had the same Fluke 88 for... maybe a few decades now. Back then, a 88VA kit (right after they upgraded to a 30a "fast test" capability) was $250, not the $550-$650 they are now.
Actually, I've seen 88-5s with no extras for under $400 on eBay. Genuine Fluke accessories will kill ya'. ;-)

Crap... forgot. Auto ranging will read resistance, and select the appropriate scale for you. Handy huh?

 

[State O' Flux]

thanks for the tips. yup, im one of those cheap bastages. i kinda have to be seeing how i dont have a whole lot of discretionary income.

Been there, more often than I'd care to remember. In fact, a water heater, furnace, new grand daughter and killer vet bills (all in the past 6 weeks) have taken my "discretionary" and made it more of a deep black hole - filled with cobwebs.

As the saying goes, I can't afford to pay attention.

 

[Kemosabe]

i "liked" it, but its really more of a "i relate to this".

i'll post back about my DMM trials/results if i have further issues.

Been there, more often than I'd care to remember. In fact, a water heater, furnace, new grand daughter and killer vet bills (all in the past 6 weeks) have taken my "discretionary" and made it more of a deep black hole - filled with cobwebs.

As the saying goes, I can't afford to pay attention.