QRPGuys 10/20/30dB 50Ω Switched Attenuator – $20
Based on an ARRL design, the QRPGuys 10/20/30dB 50Ω Switched Attenuator allows you scale back the output of your qrp transceiver to 10%, 1%, or 0.1% of its output. You can easily attenuate your low power rig to pursue your “Miles/Watt” goal. There is a bypass switch so you can easily “not attenuate” while receiving. The board is designed to accept either BNC female or the SMA female edge style connectors, however, we supply only BNC’s with the kit. The accuracy is ±1% to 100MHz. The design can be used “as is”, or allows mounting the connectors and resistors on the backside of the pcb to permit mounting in a chassis if you desire. With the use of 3W resistors, you can safely use 10 watts CW figuring a 50% duty cycle. The kit is all contained on a 3.25″ x 1.75″ pcb. On a difficulty scale of 1 to 5, 5 being the most difficult, this is rated at 1. The normal tools required are a soldering iron with a small tip, rosin core solder, and small side cutters. Allow a half hour to build, depending on your experience.