Quote Originally Posted by malc-c View Post
Tried both high (1000uf) and low (100uf) - the loco won't move
Tried, 1uf to 10uf. with a 1uf the growling was less noticable, but the slow speed control became less. Increasing this to 10uf and the loco had almost no ability to crawl.
4 - 8 kc whine? have you tried going even smaller? say .1 or .01 uf ? There is an outside chance you are not hearing the direct frequency in those motor coils but rather a beat frequency from the difference between 2 frequencies in which case you may be looking at bypassing RF.<br> I would bypass the motor from each power lead to the case too.