A Dutch hamradio station in a bookbinding workshop
Hi-Per-Mite cw filter
I ordered the kit at: www.wa0itp.com and waited a while. Then it came in the post delivery. An evening of building fun and I had it working. As an extra I build in a potentiometer.
After a while I wanted to get rid of the rf coming in the plastic housing so I rebuild the whole thing in aluminum. Much more comfortable.
On my FT-817 it performs great now. A three position switch puts power to the cirquit before switching the filter in the audio output of the rig. This eliminates heavy clicking in my headphones.