Re: [AMMRL] Frequency ocillation in wobb curve on Prodigy TCI probe

Hi Ken,

Okay, just grasping at straws, but now I think that you might be getting some crosstalk within the preamp stack itself.  I don't know how this can happen, but maybe a cable is loose or isn't properly grounded or something like that.

At the side of the preamp stack, there is a plastic cover on each of the slices which you can easily pop-off.  Once you have popped off those pieces of plastic, that will expose a ribbon cable and several other wires connecting each preamp slice to each other. 

Take a photo before doing anything, so that you have a record of which cables go where (it should be obvious, but you never know).  Carefully check that all of the cables are properly seated.  Also, as you trace the "daisychain" of cables, when you get to the last preamp slice you will probably see 50 ohm dummy load resisters.  Make sure that these are properly seated. 

If it isn't a problem with the preamp stack next to the magnet, then maybe it is a problem with the cold preamps in the probe.

Let's hope that is not the case.

Bob.