Tests and research work, dealing with several types of CW central-cathode magnetron devices, complemented with scrutiny of other authors' papers on this subject, facilitated a deep insight into the nature of the increased (abnormal) noise inherent in this type of devices and suggested effective means of its reduction. The conclusions arrived at are considered to be to a degree universal and could be widen to include a large variety of magnetron devices. (C) 2003 Published by Elsevier Science B.V.