Back in the early 1980s A.D., i was using a TCS pair as my novice license radio, along with a TV chassis for the HV, which John N., the modifier of it, called "the suicide supply". And i did get one helluva shock from it. But what i wanted to comment on was Dave Stinson's post about outboard selectivity. I had a surplus audio filter, maybe early TTY use, with a center freq of 750 Hz. Listening to the TCS with that before the headphone was like hearing a "rock throwing fight in a railroad tunnel". I didn't know enuff to consider a damping resistor. I also used the Heathkit 'Q Multiplier', 

which also worked, less echoing, but more knob twiddling. I think there were more CW stations on the air then ?

-Hue Miller