- posted
18 years ago

column in Kitplanes magazine.

However, it has been a very long time since I've done a ratiometric equation, so

would somebody please check my work? Many thanks.

I start with an air variable capacitor of 365 pf (the old crystal set tuner).

I dunk it in pure gasoline with a dielectric constant of 1.94 and I should come

up with a 708 pf capacitor.

I then mix 90 ml of pure gasoline (e = 1.94) with 10 ml of pure ethyl alcohol (e

= 24.5) and come up with a composite dielectric constant of 4.2, which gives my

capacitor dunked in this mixture a value of 1533 pf ... (which then lowers the

audio frequency of the oscillator that the capacitor is controlling, which then

goes to the frequency to voltage converter, which goes out to the Rat Shack

panel meter calibrated in percentage...)

Did I do that right? If that is correct, then all the rest of the percentages I

calculated on the spreadsheet from 1 to 10 should be OK also.

Jim