10W Micro-Diplexer for 2m / 70cm
Here’s a small 2m / 70cm diplexer that is good for up to 10W of power, perfect for working satellites with a HT. The design comes from KI0AG and was originally published in the November-December 1997 AMSAT Journal. It consists of two Chebyshev low-pass / high-pass filters designed for the 2m and 70cm Amateur Radio bands. To keep costs down, coax is soldered directly to the board and you can use heatshrink or the Yagi boom itself as a case. Slots are provided for zip-tie restraints. It does use surface mount components, although they are fairly large (1206 and 1008). This would be a great project for getting your feet wet with SMD work. The board itself is available from OSH Park (US cost is $6.05 shipped for 3 boards as of Feb. 2015) and the BOM is available from Mouser. Using the components listed below, this design is good for up to 10W of power. Keep in mind that you will receive 3 boards from OSH Park, and the Mouser BOM only has the components to build one. Up the BOM to 3 and build some with some friends!