Date: Mon, 11 Sep 2023 21:18:45 +0000
I thought I knew everything that could go wrong with this instrument after
owning it for 13 years, but here is a new one:
All probe tune displays are suddenly covered in spikes on the X channel. The
image is of the protune window, but the artifacts are there any way you look
at it. 1H and 19F on the high band look normal and spike free. The spikes
are confusing enough to the auto tune algorithm that 31P fails completely,
13C may muddle through.
What I have already checked:
it's not a probe problem, tried another probe.
not an issue with calibrating the reflection display—this is afterwards.
The ref gen boards in these consoles are a chronic problem, but I don't think
it's the problem now. Provided the probe is manually tuned, X nucleus fids and
spectra look completely normal. We occasionally (once every couple of months)
have an issue that I attribute to the ref gen board going unstable, but I can
get it to go away by turning the console off for half an hour and then turning
it back on. I was not having those symptoms when this probe tuning problem
started (unstable lock signal and distorted spectra), and giving the console
that mini vacation did not help.
Suggestions welcome! Please send them directly to me (davidv_at_caltech.edu) rather
than the default reply-all. If there's something of general interest in the
solution, I'll send it along.
David VanderVelde
Manager, Liquids NMR Facility, Caltech
davidv_at_caltech.edu
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#560): https://urldefense.com/v3/__https://ammrl.groups.=
io/g/main/message/560__;!!PvDODwlR4mBZyAb0!WUoyVu6w1in-e2nNsQ5-N5fHQR0cG8Kr=
7bCnsiQ3JZqNKlgybMZgjlVOKuZYqv4587L9oVwmOwEOHrhNVA$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/101303167=
/7559972__;!!PvDODwlR4mBZyAb0!WUoyVu6w1in-e2nNsQ5-N5fHQR0cG8Kr7bCnsiQ3JZqNK=
lgybMZgjlVOKuZYqv4587L9oVwmOwHy8yl8iw$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-
(image/png attachment: bad-protune.png)