Khan,
On the bench: Tune your coil to 125 MHz while empty. Then place it next to a saturated saline solution as the sample. If the tuning dip does not shift and broaden then you have one of those " resonances that don't go anywhere" that Dan is referring to.
Locate the resonance that does respond to the saline load and try to move it to 125 MHz.
Thanks,
David Redwine
Dow Chemical
From: Plant,Daniel [mailto:dan_at_mbi.ufl.edu]
Sent: Tuesday, March 18, 2014 2:32 PM
To: 'Khan Hekmatyar'; ammrl_at_ammrl.org
Subject: RE: AMMRL: no signal detected using surface coil in NMR
Could be something as simple as the wrong ¼ wave or filter...but many coils and circuits have resonances that don't go anywhere.
Sometimes what looks to be a nice tunable signal just doesn't work...
Send me the circuits, our RF lab might have some advice.
Dan
From: Khan Hekmatyar [mailto:nmskhan_at_gmail.com]
Sent: Monday, March 17, 2014 4:55 PM
To: ammrl_at_ammrl.org
Subject: AMMRL: no signal detected using surface coil in NMR
Hi
I built a surface coil for 500 Mhz (1H) system (Inova,Unity) and tunable to 13C nuclei ( 125.669 MHz) and when you collect spectra using a labeled 13C standard, it does not show any signal. However the same coil is changed (capacitatively) to 300Mhz MRI system (Invoa Direct Drive), it's 13C (75Mhz) channel works nicely and able to get spectra.
Any ideas, what is going on?
Thanks
Khan
Khan Hekmatyar PhD
Bioimaging Research Center (BIRC)
University of Georgia
500 D W Brooks Drive
Athens, Georgia 30602
Email: hekmat_at_uga.edu<mailto:hekmat_at_uga.edu>
nmskhan_at_gmail.com<mailto:nmskhan_at_gmail.com>
Phone: 706-583-5549 (3T)
706-542-8387 (CCRC office)
706-254-2284 (Cell)
Received on Wed Mar 26 2014 - 09:10:29 MST