Hi Folks,
If you are a Varian user, and if you do 19F{1H-Decoupling} experiments
(or vice-versa) this might be of interest to you.
Many people who perform 1H-19F double-resonance on a Varian system have
only one high-band AMT amplifier, so when we setup H-F experiments, we
have to cable through splitters and filters to share the same
high-frequency amplifier between 19F and 1H. Varian has a very nice
"Application Note" that comes with the filter-kit needed to do these
experiments, and the key point is that the AMT amplifier blanking must
be turned off (i.e. ampmode='cd') to do these experiments. There is a
significant loss in Signal:Noise when this is done.
Using a very old trick (crossed-diodes in the transmitter path), this
S:N loss can be almost completely eliminated.
Since this might be of interest to only a few people, I will only say
that I have posted a detailed .PDF file on my web-server at:
http://chemnmr.colorado.edu/ammrl/19F-Decoupling-Note-RKS.pdf .
There is also a link to this PDF document from the main AMMRL home-page.
I have been doing quite a lot of these experiments lately, and this
little modification has been extremely useful to me. I shared this with
Varian, and they suggested that I post the details on AMMRL.
Cheers,
-Rich Shoemaker
---
Richard K. Shoemaker, Ph.D.
NMR Facility Director
University of Colorado at Boulder
Phone: (303) 492-7062 Fax: (303) 492-5894
E-Mail: Richard.Shoemaker_at_Colorado.edu
Received on Mon Sep 15 2003 - 18:11:51 MST