Hi all,
The high-voltage unit on the 1H amp of our Varian VNMRS 400 MHz SSNMR system
turns itself off randomly, with the RF overload and high voltage delay LED
lights on the RF front panel coming on for a few seconds each time. The
probe and amp are tuned well and powers are normal. Once we saw the lights
come and high-voltage turn off simply on starting trtune, but more usually
it turns off after between 2 and 20 hours of use in CP experiments (3 ms CP,
20 ms acquisition time). Fans seem fine and filter has been cleaned. Can
you think of any reason why this might be happening? Thanks!
Robin
Robin Stein
MC2 NMR/EPR Manager
McGill University
801 Sherbrooke St. W
Montreal, QC H3A 0B8
514 398-6219
https://mcgill.ca/mc2
robin.stein_at_mcgill.ca<mailto:robin.stein_at_mcgill.ca>
Received on Tue Jan 05 2021 - 06:41:23 MST