The state-owned Radio Factory in Wenshang was established, and more than ten well-known university graduates, including Li Ruilai, were assigned here to develop and produce (military) transmitters, and had produced radios, pulse signal generators, band-pass filters, piling testers, cashmere moisture detectors, automatic telephone billing devices, etc. And the piling testers were of excellent quality and well-known among them in China, and continued to be produced until 1990. The improved model of 3866 signal generator is still in production today.