QRP Antenna Tuner

My 75 meter horizontal loop antenna is tuned by a home-built Z-match antenna tuner, a slightly modified version of the Norcal BLT (Balanced Line Tuner), with a resistive SWR-bridge using a super-bright LED. I could tune my 75 m loop on all bands up to and including 20 m, but at higher frequencies I could not get the series capacitor small enough. The cure was to add a switch to choose between the original primary coil with 8 + 8 turns or taps at 4 + 4 turns, after an idea by DL8RAM. This is selected by the 80-20/20-10 m switch and comes in addition to the switch between Hi-Z/Lo-Z on the secondary (the output). This tuner also tunes a 13.4 meter doublet well on 40-10 meters.

I designed a frontpanel layout for the tuner. It was generated from a text file using the program of WB8RCR. I would recommend this program for any homebrewer who wants to improve his panel layouts. I print mine on paper,