Type 12-190-60 is a low profile, high efficiency, PIN diode tuned, antenna. Intended for general airborne application, and operating over the frequency ranges 30 MHz to 88 MHz, 108 MHz to 174 MHz and 225 MHz to 400 MHz. This antenna offers a guard facility whereby performance is maintained at 121.5 MHz and 243 MHz when switched to any frequency within specified operating bands. At VHF and UHF frequencies, the capacitance between the top tube and ground is tuned out by a series of binary related PIN diode switched inductors in accordance with encoded data from the transmitter. This produces a high efficiency structure with a degree of selectivity particularly at low FM frequencies.