Hello Everyone,
After a scheduled power outage our 4-channel Inova 500 seemed to be
fine. However, the next morning the green "power on" LEDs for channels
A and B of the first amplifier (for the transmitter and decoupler one;
Herley-AMT model # 3900C-12) were flashing. I was (and am) able to run
1H spectra, but not 13C using decoupler one. When I checked again, both
LEDs were no longer flashing, but remain on continuously. The CW mode
LED comes on as it should, and the appropriate LEDs flash on the remote
status unit. I checked with an oscilloscope, and the channel B
(decoupler one) amplifier is getting an input signal (which MAY be
higher than expected), but there is absolutely no output signal.
Furthermore, the proton output is higher than before (significantly
shorter 90 degree pulse widths). I took the amplifier out and checked
inside, but nothing stood out and it is not obvious how to go about
checking the signal path etc.. Does anyone have any ideas, or
suggestions as to how we should proceed? (For the weekend we've kluged
a fix to run using decouplers 2 and 3 instead of 1 and 3 that we
normally would for these experiments, but obviously we would like to be
able to use ALL of our decouplers!)
Thanks,
Karl M. Koshlap
School of Pharmacy
University of North Carolina
Received on Mon Oct 24 2005 - 15:35:11 MST