Model 255 Cure for Physical Vibration Hum

From the Ten-Tec Reflector October 1, 2005

For anyone who has a physical audible vibration-type hum from a Ten Tec 255 power supply, I have found a solution which works like a charm. Running the supply from 230V/50Hz (like me) means that this problem is worse than when using 110V/60Hz.

I cured it by making four stand-off washers, each from four (folds) thicknesses of an old bicycle innner tube, and putting them between the transformer and its screws - it is almost totally quiet now! The damping is huge - you could put your hand on top of the transformer and feel it very vibrate very strongly - now there is virtually nothing.

Vy 73

Steve, VK6VZ