Poly Variable Capacitor Dual 335pf and 20pf
Description
These Polyvaricon type Variable Capacitors have four gangs, two 0-335pf sections and two 0-20pf sections.
The Variable Capacitors have four built in trimmers of 0-8pf each. The two 0-20pf sections have dedicated trimmers. The other two trimmers have external pin connections.
I had these special made for me by the manufacturer. The mounting and shafts are the same for all my plastic variable capacitors.
The Polyvaricon variable capacitors are a little over 3/4 inch square and 5/8 inch high. The shaft is 1/4 diameter and protrudes about 3/16 inch. The shaft and two mounting holes are both tapped metric M2.5.
With the trimmers fully open and the external trimmers not connected you can get these combinations. Sections can be connected together for different tuning ranges. There is no tracking error in connecting them together.
0-335pf + 0-20pf = 0-355pf --- With this combination you can have two 0-355pf sections.
With above combination and the Trimmers for each section set to full you can have two 16-371pf sections out of this Variable Capacitor.
0-335pf + 20pf +20pf = 0-375pf and one 0-355pf
0-335pf + 0-335pf = 0-670pf and two 0-20pf
0-335 + 0-335pf + 0-20pf = 0-690pf and one 0-20pf
0-335pf + 0-335 + 0-20pf + 0-20pf = 0-710pf
The maximum rated voltage is 100 volts.
Screws and washers for the variable capacitor are available in two lengths: 5/32" (4mm) and 3/16" (5mm).
For AM Radio match the dual 335pf and 20pf variable capacitor with the 240uh Loopstick Antenna Coil. Use one 335pf section plus one of the 20pf trimmers for a total of 355pf. You can optionally include the other trimmer to lower the frequency range slightly if needed.
CAUTION: The internal parts of the variable capacitor can be damaged easily if the screw enters the variable capacitor too far. Please check for clearance.
Shafts that fits all my poly variable capacitors are available in 12mm or 14mm length.
I have two sizes of knobs that fit the above shafts.