I used to keep a tiny CT-1 straight key as a conversation piece on my desk in past offices, but now I am using that key in my portable HF setup. So I wanted a replacement for my desk at WWVH.
I picked up a couple bare telegraph key
bases at the Dayton Hamvention this year. I used one of these bases to mount a
spare J-38 copy as my work-display-key. See attached photos.
The
circuitry next to the key forms a "code practice oscillator" using
ready-made modules I had on hand that had been purchased from Amazon. The
main item is an audio generator module ($9), with an LM386 amp module (<$1),
and a tiny speaker (<$2). I found that if I connected the key in place of the "sine" jumper on the oscillator board it keyed cleanly.
I realized the LM386 amp module was hearing a little RFI from the WWVH transmitters so I added some tiny disc caps across the inputs and output. Otherwise no mods were needed.
If someone wants a code practice oscillator that sounds good, this approach is a pretty inexpensive way to make it happen. If you drive a more sensible-sized speaker it would of course sound even better! Or headphones for private practice. I went small so everything would fit next to the key.
A friend of mine learning CW picked up the Nightfire code practice oscillator kit and he says it sounds good. It is very inexpensive as well.