Tuesday, September 27, 2022

TR-45L: Video demo of keyer memories with latest firmware; notch filter

A quickie activation today with camera rolling shows the ease with which CW memories are programmed into the TR-45L. Incorrectly recorded Morse characters, due to imperfect spacing between words, is now a thing of the past.

Also, a brief demo of the notch filter. I had hoped to make this video tomorrow during the busy CWT Sprint with lots of CW activity but we have a visitor named Ian coming to visit then, so today's the day.

Things got off to a slow start but the pace picked up later and I ended up with 32 contacts with activity on both 20 and 30 meters. The inbuilt tuner easily found a good match on 30m despite the antenna being a 1/4-wave vertical for 20 meters.     

Thanks for the calls - 'twas fun, as always...






  1. Nice video. I take it the notch is 'on' all the time, and you just turn it off to one side (hi or lo) to get it out of the passband?

    1. Hi Dave,

      I asked John WA3RNC that very question. The MIN label does refer to the audio frequency being attenuated. OUT is labeled what it is because at the frequency attenuated in this position (4 kHz), there is no audio present. Most people listen to CW at a pitch of 350 to 1200 Hz or so. The TR-45L's sidetone is 700 Hz and this is the frequency to which the radio's passband is aligned. So with the notch set to is full clockwise position, it is effectively 'OUT' of the circuit.