QRPBuilders Multi-Z Tuner – $50

Working on it…

Match Hi-Z, Low-Z, long wire, trapped wire, balanced line, and coax fed antennas with one universal tuner and SWR indicator.

 

The original Multi-Tuner is the first kit I collaborated with Doug Hendricks (KI6DS). It was our most popular kit. It’s performance and versatility has stood the test of time.

The original circuit is based on a design by Charlie Lofgren, W6JJZ. Charlie has designed tuners for years, and some of his best efforts have been in use by the Zuni Loop Field Day Group for over 25 years. Charlie designed this circuit for the Norcal QRP Club and has been around since about 2000.

Original Norcal version ~1999

Our generation of the mechanical layout makes it smaller, lighter, and much easier to assemble, while still retaining the broad versatility. 

The QRPBuilders Multi-Tuner is a Z-match design that will match a wide range of coax fed, long wire, and balanced line antennas, like high-impedance, low-loss UHF twinlead or ladder line for 40m-10m. It uses the N7VE integral led swr indicator with an absorptive bridge to protect your final transistors from a poor match. In the TUNE position, you cannot damage your transmitter caused by a high SWR. From a shorted antenna to an open antenna, your transmitter is looking at a maximum of 2:1 SWR in the TUNE position. At full brilliance your SWR is 4:1 or greater, at half brilliance your SWR is approximately 2:1, and the LED will completely extinguish at 1:1. Rated for 5 watts continuous, 10 watts intermittently, weighs (x.x oz.) and comes with female BNC connectors and optional flexibility for SMA connectors, with pushbutton connections for the long wire and balanced line connections. There is no point to point wiring like the original BLT Tuner. All connections are accomplished by mounting the components on the PCB. This kit can be built in 2-3 of hours with the normal kit building tools. On a difficulty scale of 1 to 5, 5 being the most difficult, this is rated at 2 to 3, depending on your experience.

 

Download the the assembly manual here.