This kit can be installed to improve the cut off voltage on most Yaesu FL2100 amplifiers. It is a must to install this kit when using Svetlana 572B tubes. The Svetlana 572B tubes are no longer available, but if you have an amplifier with these tubes installed it is recommended to add this Mod Kit.
Commonly used in Older Ham Radios, Heathkit, National, Kenwood, Yaesu, Ameritron, etc. Relay connector for Kenwood TL922, Yaesu FL2100Z and Heathkit SB-101, HW-101 and Collins S-Line.