Dear AMMRLers,
I've been given a UnityPlus console to replace an older Unity console
on a 1992-era (round bottom) 500 MHz Oxford magnet. The existing
console has an Oxford 18-shim power supply and the the new console
has a Varian 23-shim power supply. I have no documentation on what RT
shim stack that installed in our magnet, but it has a dual connector
going to the shim power supply and has a round plate-like aluminium
base.
I can think of two options: make an adapter to drive the 18 shims
that I know work or get a new/used 23-shim stack. I considered
swapping shim power supplies but the Unity drives the Oxford shim
power supply through an autodac board and the Varian shim power
supply is on the AP bus.
Has anyone adapted a shim power supply to a different shim stack? I
figure using 1-ohm resisters to short the 5 unused shims. I don't
know the resistances and pin-outs for my existing stack. I do have a
Oxford 23-shim stack in a 400 MHz magnet to compare. Maybe someone
has the documentation on an Oxford 18-shim stack (if that is the shim
stack...) they can lend me?
Or perhaps someone has a disused 23-shim Oxford room temperature shim
stack for a 500 MHz magnet (51-mm diameter bore) they can sell/trade
or give us?
Many thanks,
Tim
--
Timothy Burrow, Ph.D. Manager, NMR
University of Toronto 416-978-5728
http://www.chem.utoronto.ca/facilities/nmr/
Received on Mon Jul 09 2007 - 09:11:23 MST