Our air variable capacitors have a range of 1.7pf to 300pf. Each cap is constructed using precision CNC plasma cut vanes for both the stator and the rotor. Each cap includes our own contactor wheel and arm design. Our contactor arm tension is completely adjustable and does not rely on assembly pressure to hold contact pressure between the RF connector and the rotor. 

In this example, the capacitors have been installed on the bottom side of the mid-plate in our symmetric antenna tuner. Each cap has a shaft RF isolator and a 4.5:1 vernier reduction drive installed. Note the solid construction of these caps. No flimsy material being used here. Additionally, each cap is completely serviceable. These caps can be disassembled all the way down to the individual plates.

New for 2025, the 523pf air variable capacitor. This new capacitor has a maximum capacitance of 523pf (clearly...) with a minimum capacitance of 18pf. This new capacitor will be used in the ST-1500, SSAT2K and SSAT2K-AW from 2025 on.

Here's the 523pf cap installed in what was previously known as the ATU2KD. It's a big cap that can handle big power with 3-5KV spacing between the stator and rotor parts.