MD Physics

[green]

Hadn't thought about soldering problem with chip capacitors. A test with a second 10nf cog capacitor, a .1u X7R and a 1u X7R. Capacitance was measured before and after tinning the capacitor before soldering to wire loop. Including data with first 10n cog capacitor, capacitance before soldering only. Not much change with cog. Don't know if capacitance changed when soldering X7R capacitors to wire or if X7R capacitors cause L to calculate lower? Don't have a 10n X7R to try. Do have a 100n cog.

[Skippy]

Though I'm sure it would be tricky to do, you could fix the cap between the ends of the wire loop without solder. I suspect you will just experience other unknown issues, like contact resistance.

Years ago, I had a small sample of low-melting-point solder, Indium-alloy, (though some of them have Bismuth) , it melted at about 125 degrees Celcius, I recall. This looks like the kind of job it would be good for.
That "Chip Quik" surface-mount rework kit uses similar solder, I think.

[green]

Though I'm sure it would be tricky to do, you could fix the cap between the ends of the wire loop without solder. I suspect you will just experience other unknown issues, like contact resistance.

Years ago, I had a small sample of low-melting-point solder, Indium-alloy, (though some of them have Bismuth) , it melted at about 125 degrees Celcius, I recall. This looks like the kind of job it would be good for.
That "Chip Quik" surface-mount rework kit uses similar solder, I think.

Don't see away for me to try non heating connection, I'll think about it. MG Chemicals 8331S might be an option, 65deg C cure. Would have to purchase, if I could think of another use might be worth trying.

Tried another experiment with 1u X7R and 100n cog(1206 instead of 805). Started with a new 1u X7R, measured capacitance then tinned and measured capacitance again. Solder in series with 125mm AWG19 wire loop, measure resonance. Unsolder capacitor, tin again and measure capacitance. Solder in series with 125mm AWG19 wire loop, measure resonance. Repeat.

100n cog, tin then measure capacitance. Solder in series with 125mm AWG19 wire loop, measure resonance.

Added data to chart reply#76.

Looks like 1u X7R repeats capacitance if measured after being tinned. http://www.cde.com/resources/catalogs/ceramperf.pdf has a chart, capacitance vs frequency. Looks like 100n X7R would be close to .1uH but not 1u X7R.

cog data looks like it might be all right. X7R capacitor probably not good for this application.

[Skippy]

ALL high dielectric-constant capacitors are garbage, and completely unsuitable for this experiment.
I mentioned in an earlier post, polystyrene and plate mica caps would be best, they are stable and precise, plus being leaded, they will be little bothered by heat.....except they will be large, and mess up the geometry and add unknown inductance.

I'm off to the test rig thread.