• Discovery MR750 3.0T System Service Methods
  • 5690009-2EN Revision 4
  • Object ID: 00000018WIA30601450GYZ
  • Topic ID: id_2021716 Version: 2.1
  • Date: Oct 11, 2021 6:20:13 PM

Installing the MNS exciter

Procedure

  1. Install the new MNS exciter in the PEN cabinet.
  2. Connect the exciter cables appropriately.
  3. Replace the thumbscrews to secure the exciter to the PEN cabinet.
  4. Remove LOTO from the RF amplifier and PEN cabinet (magnet room electronics). See the MR Service Safety Manual, PN 5452735.

Finalization

Topic ID: task_aq3_vdh_nkb

MNS Exciter Calibration

Prerequisites

The nuclei that are calibrated by default are 13C and 31P. To guarantee a linear output from the MNS exciter at other frequencies, you can edit a config file to specify which other frequency(ies) the site needs calibrated. This config file controls which MNS frequencies are used when calibrating the Transmit Gain tables of the MNS exciter. To choose frequencies to calibrate, open the config file and change the value for the desired frequencies from 0 to 1. The calibration happens during the next TPS reset or system restart. This calibration uses the loopback path only. No RF is sent to the broadband amp. The system only needs to be configured for MNS with the standard MNS hardware (exciter, cabling, and so on). It is not necessary to connect an MNS TR module during this calibration.
Note: Each additional frequency calibration will add time to the TPS reset. Calibrate only the nuclei that the site needs; do not calibrate them all.

Procedure

  1. In a C shell, go to the directory /w/config
  2. Type gedit mnsTgCal.cfgEnter
    The mnsTgCal.cfg file contains a list of available nuclei.
  3. For the nuclei that the site needs calibrated, change the value from 0 to 1.
  4. Save the file.
  5. Type more mnsTgCal.cfgEnter and confirm that the changes were saved.
    At the next TPS reset or system restart, the nuclei will be calibrated.
  6. After installation is complete, see MNS Amplifier Calibration.