Determining the charge-to-mass ratio of the electron using old TVs: A low-cost approach

In this work, an innovative and low-cost experimental setup was developed to measure the electron charge-to-mass ratio (q/m). It uses a cathode ray tube (CRT) obtained from an old mini-TV. This paper shares plans for constructing the required electromagnet, its power supply, and a high-voltage source for accelerating the electrons in the CRT. The experimental setup can cost as little as $40. The electron beam displacement on the CRT screen can be used to determine the q/m ratio, making this an effective approach for modern experimental physics in high school and undergraduate courses.