A survey of the operation of the five model 4130 (nominally 3 MV) Tandetron accelerator systems currently in use for accelerator mass spectrometry (AMS) is presented. Specific attention is paid to components which are critical for long-term stable and noise-free operation and the monitoring of X-ray emission from the accelerator section is described as a possible diagnostic tool. An important requirement for the heavy-element analysis program at IsoTrace, the terminal voltage stability, is discussed. © 1990.