HELLO. I HAVE AN ATWATER KENT MODEL 89. ALL THE WIRES HAVE BEEN REPLACED. I HAD TO REPLACE ALL THE FLAT RESISTORS AS WELL. THE PROBLEM NOW IS THE FILTER COND. WHAT IS A 2.3 MFD? OR A .25 MFD AND WHERE DO I FIND A REPLACEMENT. THIS IS INSIDE A VERY LARGE TYPE CAN. ANY IDEAS ARE WELCOME. THANK YOU, PAUL M

http://www.atwaterkentradio.com/

http://www.nostalgiaair.org/PagesByModel/518/M0001518.pdf

The 2.3 and .25 MFD caps are most likely paper caps. The 2.3 MFD caps are the filter caps. They store energy and release it when the energy available from the rectifier drops (the rectifier sends out 120 pulses a second....each pulse is half of a sine wave, and all are of the same polarity, and are right next to eachother......the space between each peak is, of course, lower than the peak, and requires filling in, if you are to have smooth DC). The .25 MFD cap is a tuning cap and forms a tank circuit with its corresponding choke. The tank circuit resonates best at 120 cycles per second, making it most efficient at that frequency (rather than having a broad bandwidth filter). With the cap's current leading by 45 degrees and the choke's current trailing by 45 degrees, the two work to fill in the low spots in the current coming from the rectifier.

If you wish, you may either stick with original values, which can either be paper or electrolytic, or you can change the 2.3 MFD caps to 10 or 20 MFD caps, and eliminate the .25 MFD caps. I'd stick with original values first.

T.