User name Yi Qiang et al.
Log entry time 23:37:03 on October 15, 2008
Entry number 243714
keyword=Self-resonancing of NMR pickup coilsWe observed self-resonancing at about 70-90 kHz from all pumping chamber pickup coils (coil inside the oven have a resonance at exactly 91 kHz). Adding a 10.5 m extension cable will shift the resonance to lower frequency and even longer calbe does not help much here. So we will need to make six 12 m extension cables to all pumping chamber pickup coils.
ps: Yi', please make 6 12 meters coaxial cables tommorrow and you will
find a new spool of cable in the hall.
A copy of this log entry has been emailed to: yqiang@jlab.org, chian@jlab.org, jinhuang@jlab.org, jpchen@jlab.org, zhangyi@jlab.org
Q-curve without extension cable
Q-curve with 10m extension cable