For sale: National Co. 5 Henry choke / autotransformer A-17847 Q is 10 at 100 cps. Rated for 1 mA DC. Test voltage is 500 volts DC. Has taps for +/1 2% 40% 95% 100$ 105% and encased in a neat-looking gray case 1.5" X 1.5" X 2.5" tall. Will sell for $10.00 Visit my web pages at: http://home.cfl.rr.com/happysurfer/