Budget Precision Reference Capacitor

[Terabyte2007]

I picked up an NOS Silver Mica precision 173200 nF (0.1732uF) .3% capacitor to use as my budget reference capacitance source. Reference checked against an Agilent Capacitance Meter at 173.12 nF, it's well within tolerance!  Gotta love the old Russian military NOS.

[SeanB]

I picked up a pair of 1uF precision caps as well at the scrap yard. 1uF 0.1% 200VAC at 20C, and as far as I can check they are still within specs, even with the trimming method used inside of adding polystyrene caps in parallel to up them to the correct value.

[Terabyte2007]

I picked up a pair of 1uF precision caps as well at the scrap yard. 1uF 0.1% 200VAC at 20C, and as far as I can check they are still within specs, even with the trimming method used inside of adding polystyrene caps in parallel to up them to the correct value.

I would like to get a couple .1% but could not find any. Nice score!

There is always this! 

http://www.ebay.com/itm/IET-General-Radio-1408-Air-Bath-Reference-Standard-Capacitor-/270881619941?pt=LH_DefaultDomain_0&hash=item3f11cd7fe5

[SeanB]

Yes, but I could buy a house for what one costs though.

[Terabyte2007]

Yes, but I could buy a house for what one costs though.

You are correct sir! Nothing I would ever consider. 

[SeanB]

I could post you the half kilo block if you want, when SAPO decides to get off thier asses and back to work. At present the only way to send to the USA is via courier, and that is $150 per kilo, or for the first 3 pounds. That is kind of expensive.

[Terabyte2007]

I could post you the half kilo block if you want, when SAPO decides to get off thier asses and back to work. At present the only way to send to the USA is via courier, and that is $150 per kilo, or for the first 3 pounds. That is kind of expensive.

Ouch! I still may be interested, I'll let you know. Thanks!

[bingo600]

I was lucky to get my hands on a HP 4440B for $88 incl shipping locally in DK 

Decade w. 0.25% precision.

https://www.eevblog.com/forum/projects/reference-for-lcr-or-esr-meters/msg365032/#msg365032
https://www.eevblog.com/forum/testgear/iet-de-5000-lcr-meter-in-uk/msg197797/#msg197797

That was a nice score.

What does the "russian" cost ?

/Bingo

[David Hess]

The best reference capacitor I have access to is inside of an ESI 250DA impedance bridge.  The specifications in the parts list say that it is 0.099880 microfarads +/- 0.1% and trimmed to 0.1 microfarads externally.  I do not have any way to verify its calibration but as far as I have been able to determine, it has not drifted since it was manufactured on June 28th of 1965 as shown in the photograph.

[SeanB]

This is the one I got from the scrappie...

http://mjlorton.com/forum/index.php?action=dlattach;topic=713.0;attach=2894;image

[David Hess]

This is the one I got from the scrappie...

http://mjlorton.com/forum/index.php?action=dlattach;topic=713.0;attach=2894;image

Registration is required to view.

[Terabyte2007]

This is the one I got from the scrappie...

http://mjlorton.com/forum/index.php?action=dlattach;topic=713.0;attach=2894;image

Did you get it with the case and all?

[SeanB]

I did, just lifted the skirt to have a peek inside. Measured it and it is likely still within limits, or at least agrees with the capacitance meter.