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Chris <cbx@noreply.com>: Jul 16 01:29PM I'm finding I get different results (vastly different in some cases) when measuring the total resistance of a circuit with a) a DMM and b) an old analog meter with a physical needle. And this doesn't only happen at high impedance points, either. What could account for this?   I've got four DMMs and two analogs. The DMMs agree with the other DMMs and the analogs agree with each other. But the different types don't agree with each other!

tabbypurr@gmail.com: Jul 16 06:39AM -0700 On Sunday, 16 July 2017 14:33:04 UTC+1, Chris wrote:   > I've got four DMMs and two analogs. The DMMs agree with the other DMMs > and the analogs agree with each other. But the different types don't > agree with each other!   Are they calibrated?     NT

John-Del <ohger1s@gmail.com>: Jul 16 07:01AM -0700 On Sunday, July 16, 2017 at 9:33:04 AM UTC-4, Chris wrote:   > I've got four DMMs and two analogs. The DMMs agree with the other DMMs > and the analogs agree with each other. But the different types don't > agree with each other!       Do your DMMs and analogues agree with each other when using fixed resistors out of circuit?

Chris <cbx@noreply.com>: Jul 16 02:08PM On Sun, 16 Jul 2017 07:01:34 -0700, John-Del wrote:   > Do your DMMs and analogues agree with each other when using fixed > resistors out of circuit?   Yes they do. Sorry, should have mentioned that in the OP.

Ralph Mowery <rmowery28146@earthlink.net>: Jul 16 10:41AM -0400 In article <okfpn3$djj$10@dont-email.me>, cbx@noreply.com says...   > I've got four DMMs and two analogs. The DMMs agree with the other DMMs > and the analogs agree with each other. But the different types don't > agree with each other!   If you are measuring in circuit resistance of solid state circuits, then you often will.   The analog meter has enough voltage/current to turn on the junctions of diodes and transistors. The DMM will not have enough to turn them on.   If you have a diode out of the circut and use an analog meter you will often see a small resistance in one direction and if you reverse the leads a high resistance. The DMM will usually show a high resistance in both directions unless you use the diode setting if the dmm has one.

Mike Coon <gravity@mjcoon.plus.com>: Jul 16 03:43PM +0100 In article <okfs1a$djj$11@dont-email.me>, cbx@noreply.com says...   > > Do your DMMs and analogues agree with each other when using fixed > > resistors out of circuit?   > Yes they do. Sorry, should have mentioned that in the OP.   Yes, and have reversed the leads as Ralph suggests...   Mike.

Cursitor Doom <curd@notformail.com>: Jul 16 03:05PM On Sun, 16 Jul 2017 10:41:02 -0400, Ralph Mowery wrote:   > often see a small resistance in one direction and if you reverse the > leads a high resistance. The DMM will usually show a high resistance in > both directions unless you use the diode setting if the dmm has one.   Damnit, Ralph! You beat me to it. I was going to say that. ;-) I have a couple of analogue meters too. They test for resistance at 15V which is more than enough to turn on those semiconductors, but also more than enough to destroy a lot of chips that can't tolerate much more than 5V. Horses for courses/different strokes and all that.

N_Cook <diverse@tcp.co.uk>: Jul 16 04:36PM +0100 On 16/07/2017 14:29, Chris wrote:   > I've got four DMMs and two analogs. The DMMs agree with the other DMMs > and the analogs agree with each other. But the different types don't > agree with each other!   Try with different probe leads and resistors with different termination metals, maybe small dissimilar metals producing voltages that are interpreted differently by the different metering systems

Chris <cbx@noreply.com>: Jul 16 04:26PM On Sun, 16 Jul 2017 16:36:56 +0100, N_Cook wrote:   > Try with different probe leads and resistors with different termination > metals, maybe small dissimilar metals producing voltages that are > interpreted differently by the different metering systems   It's okay now I believe Ralph has nailed the problem entirely in his post. (thanks, Ralph).

Cursitor Doom <curd@notformail.com>: Jul 16 03:15PM On Sun, 09 Jul 2017 13:24:04 -0500, Tim Williams wrote:   > have dried out caps (excess ESR).   > Yes, the nippley appearance is likely ESR. But, if you say it's okay, > then it must be okay. Right?   Do I detect a note of scepticism here, Tim? I've checked all the electrolytics with my ESR/Capacitance tester which is claimed to be able to test for ESR in-circuit so I didn't remove any of the caps in order to test them. I'm relying on the meter manufacturer's claims that it's not necessary to do so and in the absence of any evidence to the contrary, I don't see what more I can do.

Herb Bisside <herb@bisside.com>: Jul 16 09:32AM -0400 On 7/15/2017 9:49 PM, Ed Pawlowski wrote: >> The target audience to buy your used car is a half-broke teenager. They'll want a car with a USB port on the stereo.   >> If you wanna sell your car, put one in. Get it yet, Gramps?   > Sure, put a $200 radio in it and get $50 more for the car. Let the kid put in his own music of choice.     How does $28.99 work for you?   https://smile.amazon.com/Bluetooth-Wireless-Control-Included-Xshop/dp/B06XR3ZLJF

Ed Pawlowski <esp@snet.net>: Jul 16 11:11AM -0400 On 7/16/2017 9:32 AM, Herb Bisside wrote:   > How does $28.99 work for you?   > https://smile.amazon.com/Bluetooth-Wireless-Control-Included-Xshop/dp/B06XR3ZLJF   That could work. If it is a decent radio it is damned cheap for the features. That could pay for itself.   Seems like a few years ago a crappy Sparkomatic AM radio was more than that.

bitrex <bitrex@de.lete.earthlink.net>: Jul 16 10:57AM -0400 > Now you know why there is so much violence on TV....... > (But there is hope......Removing those guns will stop all this TV > violence permanently)..... <LOL>.   <https://www.youtube.com/watch?v=NpYEJx7PkWE>

ABLE1 <someone@nowhere.net>: Jul 16 09:54AM -0400 On 7/16/2017 7:51 AM, Phil Allison wrote:   > The CRC product you linked is likely similar - simple, fast evaporating hydrocarbon solvent.   > .... Phil   Thanks Phil,   Most impressive....................   and they do Chocolate as well.............   COOL!!!     Les

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