In this schematic, there is an unfamiliar notation for the variable capacitors using and division sign or obelus, for example 2÷10p (red), as opposed to, e.g. 1p for a fixed capacitor (green).
I have presumed that this is used for indicating the number of air gaps in a rotary variable capacitor, as the total capacitance is the capacitance of one gap, divided by the number of gaps (or plates – 1):
\$\frac{C_{one\ gap}}{n_{gaps}} = \frac{C_{one\ gap}}{n_{plates} – 1} = C_{total}\$
Is this the correct interpretation?
Best Answer
By Occam's razor, I would interpret the markings as the range of capacitance for the trimmers, and that it's a regional or idiosyncratic use of ÷ rather than ~ or -.
This is confirmed by the text on the website- for example here.
Mechanical engineers sometimes indicate ranges by putting one number above the other, separated by a horizontal line, which, of course, is what ÷ is shorthand for.