On Sat, 15 Sep 2018, 12:14 Andrea Baldoni, <[email protected]> wrote:
> Hello. > > > I have not a ceramic or glass bar long enough to test it. > > I am curiuos if the effect could be due to the change in dielectric > constant > between air and the pipe material, or the pipe itself that, despite being > clean, is not a so good insulator, even at low voltage (about 10V) and > moderately low frequency. > > Best regards, > Andrea Baldoni I would have thought it more than likely. It is well known capacitance of capacitors very with the temperature with some types being much better than others. I recall someone selling some "standard capacitors" on eBay his company had made years ago. He claimed they were much better than the HP ones, but I don't know if that is true or not. He also made the point that being several years old, their stability would have been lower than recently made capacitor. PTFE has the annoying characteristic that its temperature coefficient is highest around room temperature. I have had some useful with someone at NPL about liquid dielectrics at RF. Dave. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
