An instrumental setup is described which permits one to look for and investigate NMR signals in nanocomposite magnetically ordered substances or in bulk ones under improper experimental conditions. The setup is designed to operate in a frequency range from 10 MHz to 800 MHz using fast digital data acquisition and coherent storage in two different modes: spin echo mode and stochastic NMR mode. Several examples of detected echo signals are included.  After some modifications the setup could be used for express-evaluation of products, semi-products and raw materials in metal smelting processes of ferrous and non-ferrous metallurgy.