Dear NMR Community,
The School of Natural Sciences at the University of Newcastle-upon-Tyne
remain the proud owner of a functional Bruker WM300 (Wide-Bore) NMR
spectrometer !
A proton spectrum of a mixture of (MeO)3B and C6H6 was successfully
obtained at around 1800 HRS on Sunday 24th October 2004.
When I took up my appointment at the School in mid-February of this year,
I found this spectrometer in a sad state of non-service and disrepair. It
had been in this state for quite a significant period of time (around 2
years to the best of my knowledge) following a hard disk drive crash.
The magnet however had been kept energised throughout this period. Hence,
with extensive assistance from my fiancee, Dr. H. Rao (a mere biochemist
with an innate knowledge for all things engineering), we embarked together
on a restoration journey that has given us a unique insight into the "nuts
and bolts" of an NMR spectrometer.
For anyone out there still maintaining a Bruker WM-series NMR spectrometer,
I include in this email a manifest of our simple restorative efforts on
the WM300WB, conducted in-house. We would be pleased to hear from other
members of the NMR Community who are undertaking similar stimulating
endeavours.
"Does Anyone Have a Spare Frequency Synthesiser?"
=================================================
I would like to take this opportunity to thank all those who responded to
my email regarding the failed PTS160 unit (subject: Does Anyone Have a
Spare Frequency Synthesiser?):
Kind advice from:
W.C. Stevens, Southern Illinois University,
G.A. Morris, University of Manchester,
G. Daelen, Namur, Belgium,
A.M. Kenwright and I. McKeag, University of Durham,
C.A. Anderson, University of Utah,
D. Cross, RototecSpintec GmbH,
G. Coumbarides, Goss Scientific,
Kind offer of replacement PTS units from:
G.A. Lawless, University of Sussex,
V.P. Chacko, JHU,
B. Crysell, University of Cambridge (special thanks to D. Howe),
M. Robertson, University of Edinburgh.
Offers of support kindly received from:
NMR Associates (A.C. Itkin).
The fault on our PTS160 was indeed in the power supply !
Manifest of Works Undertaken
============================
1. Replacement of the failed NEC D2246 SMD-type hard disk drive with a
brand new Hitachi DK-512S-17 SMD-type hard drive (secured by Dr. Stuart
Hill before his retirement as a backup unit for our Bruker AC200F NMR
spectrometer).
2. Successfull establishment of bi-directional communication between the
Aspect 3000 spectrometer-control computer and the new hard disk drive,
followed by formatting of the new hard disk drive.
3. Installation and configuration of the ADAKOS operating system.
4. Installation and configuration of the DISB94 spectrometer-control
software.
5. Diagnosis and repair of a failed power supply unit on the PTS160
frequency synthesiser unit (It was the 2N6492 NPN Darlington power-transistor
within the 5.4 V DC side of the internal power supply of the PTS160 that
had burnt-out).
6. Diagnosis and repair of the 10 MHz local oscillator board located
within the frequency box of the spectrometer (an electrolytic capacitor
had fried on the circuit board and we replaced this with a modern
component of equivalent specification).
7. Repair of the main power supply unit for the spectrometer (a slow-blow
fuse had blown on a DC voltage supply rail serving the LO board within the
frequency box).
8. Resolution of a problem with intermittent failure of the 8" floppy disk
drive unit on the spectrometer (simply by matching the voltage supply
setting of the internal power supply unit of the 8" floppy disk drive unit
to the voltage of the dedicated mains supply cable for the disk drive unit
from the WM300WB spectrometer).
9. Overhaul of the compressed air supply connections to the WM300WB
spectrometer to fix various leaks in the system.
10. Emergency diffusion pumpdown of the outer vacuum chamber of the
WM300WB cryostat to reduce an elevation in the boil-off rate of liquid
helium observed some months ago (and thereby prevent the magnet from
quenching).
11. Emergency replenishment of liquid helium for the WM300WB magnet during
the onset of elevated helium boil-off some months ago (to prevent the
WM300WB magnet from quenching).
Acknowledgements
================
The successful restoration of the Bruker WM300WB would not have been
possible were it not for the kind technical input of the NMR team at
Bruker-Biospin in Coventry. We would like to especially thank Ian Francis
for all the advice given over our conference (!) phone.
I am grateful to Dr. M.N.S. Hill, who maintained the WM300WB for over 20
years before I arrived on the scene, for snippets of tips and tricks.
I would like to thank Mr. G. Robb (Physics, University of Newcastle-upon-Tyne)
for advice and kind long-term loan of an oil-diffusion pump.
I wish to thank the following individuals for invaluable advice relating
to steps 10 and 11 of the Manifest of Works:
I. Francis, Bruker-Biospin,
T. Wheeler, Oxford Instruments,
S. Levandowski, CPC-Cryolab,
L. Harrison, Tamo Ltd.
Yours sincerely,
Phuong Ghi.
===========================================
Dr. P.Y. Ghi
NMR Centre Manager
School of Natural Sciences,
University of Newcastle-Upon-Tyne,
Bedson Building (Chemistry),
Newcastle-Upon-Tyne, NE1 7RU,
United Kingdom.
Tel: +44-191-222-6851 (Direct Line)
Fax: +44-191-222-6929 (School Office)
Email: nmr@ncl.ac.uk
Web: www.ncl.ac.uk/nmr
===========================================
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