This small tube power supply is made by Farnsworth Television & Radio Corp, Ft. Under Signal Corps Rectifier Model RA-20. I have used this to run an old Jensen M18 field coil speaker few years back and it works very well then. Now it probably will need capacitors and resistors replaced as necessary. You will need an old round twin flat AC plug.I do not have one. Mine is a circular twin flat which I temporary use to power it up. No AC cord is included. The rectifier tube is a 5Y3 vacuum tube.
Thank You and Good Luck :. The item "Tube Power Supply For Jensen M18 Field Coil Speaker 300VDC @ 2amps Maximum" is in sale since Sunday, November 22, 2020. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "mono" and is located in Fairfax, Virginia.This item can be shipped worldwide.