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).

Schematic fragment

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?


1 Answer 1


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.

Capacitive trimmers (Philips foil type, 7.5mm diameter with three leads) in the 106MHz and 213MHz bandpass filters are increased to 5-40pF (violet body), while the trimmers in the output stage at 425MHz are increased to 4-20pF (green body).

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.


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