HELP! AADE L/C meter

Holy Crap!!

Ya, I would recheck that 1194pf, if I got near that number again, I'd probably check a third time with a different method.

FWIW, last night I checked three 25uH inductors I wound with my AADE. Tonight I checked three more and they read about 80uH. I retested the three from last night, they also tested about 80uH. Did I mention I left the AADE on all night? I installed a new battery and they all tested near 25uH. The battery voltage was 7.94 Volts. I don't know how capacitance readings are affected. Mikek

Re-measured..T1 T2 Protek 6500 1.27 0.07 nF Mastech MY65 1246 66.7 pF Implies the AADE read T1 low.

( See earlier posts )

But, the AADE is close enough for the purpose. My problem is that I cannot make my model fit all your data at this point. If I put the

1200pF into my model, the second resonant point above 1MHz pretty much disappears. Apparently, my model does not represent your device.

I think the reason for this is that the Pri-Sec capacitance is distributed over the length of the winding due to the bifilar winding. I can't do that in my model.

I have to give up on this. Sorry.

Well, you can sort-of emulate that by breaking the transformer up into N pieces, which busts the capacitance for each piece by a factor of N. It is a bit of a PTA in Spice to do that, especially as N gets larger. Try as 1st cut N=5 then N=10 to get an idea how helpful that trick is, and a guesstimate what N "should" be for a reasonable emulation.

Yes, of course. But, my interest was in helping you to answer your question(s). I have no idea whether I helped or not, but it appears that you know much more about this than I do, so I think I am not needed for the rest of your investigation.

Seems to me that i learned a bit...especially about the AADE WRT measuring inductors. Problem is that the "make it part of an oscillator" scheme can be doomed to failure because (relatively) large currents can flow. The large current can easily push the inductor toward saturation, at least part of the cycle. And here is no practical way to limit the amplitude..

I'm not sure the high current is true, I measured the voltage across an inductor the other day, and didn't think the voltage was very high. I don't recall the numbers. Do you have a scope? Look at it. Mikek

• SNIPPED due to aioe *

Amplitude according to SPICE can be almost FOUR times pk-pk of battery. Which means 36V from a 9V battery. Waveform far from a sine..and similar to what i saw once with scope. Don't remember amplitude,but it was pretty big.

I will look again but, when I looked the first time I was unimpressed with the voltage across the inductor, when using the AADE meter. I need to make a 22mH inductor, don't think I have anything like that around home. Mikek

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Ok, I came up with a 21.6 mHy inductor when measured with the AADE meter. The voltage across the inductor is 1.2 Vpp measured with a X10 scope probe, (20mv scale). The probe capacitance changed the AADE reading to 22.4 mHy. ~ The frequency was just over 40kHz. I found a schematic here. It's Japanese, you might find one in English.

Here's a spec site.

Hope that helps, Mikek

Fired up the AADE and scope 10X probe; 1.5Vpk-pk amplitude for te air-core inductor picked on purpose so saturation would be impossible. Certainly not the 36V that a Colpitts or Hartley might give (according to SPICE), but a heck of a lot higher than the 10mV(? forgot actual value used) level i used on the RTTY coils.

Check; same as what i got: Fired up the AADE and scope 10X probe; 1.5Vpk-pk amplitude for the air-core inductor picked on purpose so saturation would be impossible. Certainly not the 36V that a Colpitts or Hartley might give (according to SPICE), but a heck of a lot higher than the 10mV(? forgot actual value used) level i used on the RTTY coils. Wow! The Japanese one has rather detailed assembly.

The assembly plans in English are the same, I just didn't find it. I'm not sure if the page is down because the owner is ill, or I didn't know where to look. I didn't try very hard. Re: My coil, I have large bobbin wound that measures 14.4mH. I have potcore that fits the bobbin, I positioned the bobbin in the halfcore until I had 21.6mH. If I drop it all the way in the half core it measures 56.3mH. When I put both halves on the bobbin the inductance goes way over 380mH. 380 is as high as my AADE gets before it goes haywire. Mikek

Robert Baer added:

Try and compare with AADE: M8(M328) Transistor Tester Kit, Sold by: King so on Amazon

This is an amazing device that can test resistors, capacitors, inductors,diodes and transistors.

Transistors: displays NPN/PNP; E,B,C leads; beta; Vbe. Diodes: use leads 1,2; shows polarity; Vf, capacitance Inductors: connected leads; inductance; resistance. 100uH to least 80mH, insufficient part range to characterize. Capacitors: connected leads; capacitance; ESR. 33pF to 10,000uF and more. Resistors: 50 ohms to 40Meg; above that accuracy suffers.

SMD patterns for testing: 1206, 0804, 0603, 0402, SOT23-3

If unable to determine part, reading is: "No, unknown, or damaged part"

Readings appear to be 1% or better.

Can you give a better lead? I could not find it on Amazon. Mikek

Try " M328 meter" on Ebay. The cheapest one is $10.50 plus $2.00 shipping.

Dan

At present,the second one shown (sorted by price, eBay item number:

400789166273) with red PCB and no ZIF socket was the one i got. On Amazon at a slightly higher price.

These things are amazing; a micro-controller, some 1% parts,and software.