- Jan 1, 1970
In the ungrounded lead. As I said, you can probably get away without it.
This is a thermocouple input, and it's heavily lowpass filtered by RCs, and then
by software filtering. The tc cable is a shielded pair. Unfortunately, the tc is
inside an NMR probe, along with high field levels of RF in the 50-500 MHzrange.
The RF did (always will) get into the signal conditioning opamps and get
rectified to small offsets, in a system where 1 microvolt matters. I added this
and it helped by something like 30 dB, and especially broke up narrowband
I got this business by doing this better than their previous vendor. An RF
generator could shut down his controller from clear across the room. I'vesold
over 3000 controllers so far, not bad for a "stinkin bead."
"Good bead" :^)
Say if you passed one of the TC leads through it in the other
direction would that make it a one turn CM choke? (Just trying to
expand my transformer understanding.)