Thank you to all those who responded.
We went through several test and finally solved the problem after replacing
PTS. Unfortunately, none of the tests could clearly isolate the problem to
PTS and the errors were pointing us in the wrong direction. Our lock signal
was perfect too. Here is a summary of various suggestions and every one of
them was very valuable.
1. Check wobb with a different probe to isolate that it is not a
probe-related issue. Many suggestions were to test probe and preamp
2. wobb ext50 to check if it is not due to a busted preamp.
3. check all boards tcu, fcu, rcu through system tests and measure freq
outputs - 80 MHz, 22 MHz and voltage at PTS and at tune-in at preamp. The
error we got on the tcu test clearly was incomprehensible.
4. Check all cables to probe and see if any of them was switched.
5. It can be RXAD board - experienced by Timothy Burrow at Univ. of
Toronto.
6. It can be a faulty PTS (which turned out to be right for our problem).
Bruker engineers were very supportive while I tried to isolate the problem.
Dr. Gopal Subramaniam (718-997-4123)
Department of Chemistry & Biochemistry
Queens College - CUNY
Flushing, NY 11367
Received on Thu Apr 07 2011 - 11:22:10 MST