Jennings Vacuum Variable

This is a Jennings model CVDB 1500 15N25 vacuum variable. It's 36 through 1500 pF at 15,000 VDC. I measured one and at the low end, it measured 30 pF. I'm using this one for my own HF antenna tuner. It may have a small dent but the vacuum has not been broken.

I have 1 of these left removed from Collins 208U linear amplifiers. I also have a 2-phase servo to drive the capacitor electromechanically. See these listed on the Miscellaneous page.

Jennings Vacuum Variable

This is a Jennings model CVDP 2300-15S vacuum variable. It's 50 through 2300 pF at 15,000 VDC. It will handle at least 100 Amps RMS up through 100 MHz and 200 Amps at 2 MHz.

I have 1 of these big boys left, removed from Collins 208U linear amplifiers. I also have a 2-phase servos to drive the capacitor electromechanically. See these listed on the Miscellaneous page. There may be an inconsequential dent or two on the body.

Resonant Tank

This parallel resonant tank is from a Collins CU-1464 antenna tuner. The range of resonance is 6.5 MHz through 8.5 MHz. The Jennings vacuum variable capacitor model UMF-800 is rated at 18,000 VDC and is 12 pF through 800 pF.

High Voltage RF Plate Coupling Cap

This is a 2000 pF, 10,000 VDC coupling capacitor. It has very low inductance, and can carry 100 Amps of RF at all HF frequencies.

High Voltage RF Bypass Circuit

There are 2000 pF low-inductance bypass capacitors at the ends of a choke which traverses the middle of the tube.

This capacitor/inductor unit passes 7500 VDC from the lower compartment, through the RF deck to the anode compartment. The top end then is connected to the plate voltage supply choke (listed under Inductors) which is directly connected to the tetrode's anode.

Jennings Vacuum Variable

A nice variable for that antenna tuner, or for use in a pi network on the plate of that new linear you're thinking of building...

Jennings Vacuum Variable

This variable has the hardware to operate the capacitor already installed. Simply rotate that gear on the end, and the cap traverses its range with mechanical stops built in.

Resonant Tank

A tank circuit with a variable inductor and air dielectric variable capacitor. The circuit resonates from 1.8 MHz through 32 MHz and was in the plate circuit of a driver for the grid of a 4CX10000D linear.

Large Electrolytic

This is a large aluminum electrolytic rated as 12,000 uF at 250 VDC. I have several, so series a few to get up into the kilovolt range with lots of Joules.

Large Electrolytics

This is a large aluminum electrolytic rated as 160,000 uF at 10 VDC.

I have a myriad of aluminum electrolytics which I am going to purge from my stock soon. They range from 10 VDC through 350 VDC in various capacitances. Please ask if you need any particular value, and expect the cap if I have it, to be practically free...