I found Professor Michal's paper you reference very useful in working up an EF-NMR project. Also the background information on the Terranova-MRI machine from the New Zealand company, Magritek (http://www.magritek.com/products/terranova/). Some great videos on the site explaining basic theory, pulse sequences, etc.

I wrote up my practical experiences with a successful project in Chapter 8 of the book, Discovering the Quantum, for the Amazon Kindle platform ( ASIN: B07B4XTRGY  ), which is available from Amazon.com at the token price of $1.99.

The biggest problems proved to be interference from harmonics of the mains frequency and the inhomogeneity of the earth's field in a suburban environment due to steel in appliances and reinforced concrete buildings.

What are your plans?  Do you want to replicate the spectrometer described in the paper or modify the design significantly?  Also, ultimately, what do you want to use the spectrometer for?

Right now, I am just trying to replicate the design to get some experience. Once I get confidence, I will try to add gradient coil to build imaging system. My plan is to use it to measure relaxation times (T1, T2) from the different samples including some biological samples.