The new JLC series of high-Q variable coils from Johanson Manufacturing, available from Richardson Electronics, offers a wide tuning range of 30 to 133 nH and self-resonant frequencies of 700 to 1500 MHz, which make them appropriate tuning devices for many RF applications. These coils also feature a non-magnetic core for use in MRI systems or other magnetically sensitive circuits. Sample kits (JMC-SMTCOIL-KIT), which include 3 pieces each of 6 different Johanson variable coils (surface mount) and a tuning tool, are available from stock to simplify the component selection process. In addition to the MRI applications, these coils are used in RF amplifiers, RF test and measurement systems, and defense electronics systems. With an overall height of only 0.35 inches, these variable inductors are well suited for applications where low-profile circuit boards are essential. Tuning is done by means of a threaded PTFE and non-magnetic copper alloy core.