AM Radio Variable Capacitor & Thumbwheel Knob 60+140pF, 200pF

AM Radio Variable Capacitor & Thumbwheel Knob 60+140pF, 200pF Description

Dual 2 Section MW Variable Capacitor 60+140pF, 200pF Thumbwheel Knob & Screws

This is one item of new polyethylene dielectric dual gang variable capacitor which comes with two M2.5 countersink type mounting screws and a large plastic thumbwheel knob.  The mounting screws should be used with care.  If they are screwed-in too far with no intervening front panel they may foul the internal parts.  The screws are cross head types but they are easily used with a small 2mm flat-head screwdriver.  The two capacitor gangs are designed for standard MW radio use, those being a 4 to 60pF oscillator section and a 4 to 140pF antenna section.  Two 12pF trimmers are present on the rear for superheterodyne alignment.  For simpler projects the two sections connected to the outer two wires would be connected together to form a 200pF variable capacitor, and the trimmers set with the vanes un-meshed for minimum additional capacitance.  The connections are shown in a sketch in the additional pictures.  The case body measures 20 x 20 x 12mm and the shaft extends 4mm from this.  The thumbwheel knob is 41mm diameter and 2mm thick.  The screws are cross-head types but the heads are such that a 2mm flat blade screwdriver can be used without trouble.

If you want to make solderless connections, you can do that quite easily using a 3 amp terminal block (not provided) as shown in one of the secondary pictures, where the capacitor is shown wired as a single 200pF unit.

You can use these in various radio projects such as crystal sets and receiving loop antennas.