This unique unit was provided courtesy of Jack Ward, world renowned collector and historian of all things CK722: http://www.geocities.com/ck722transistor/.
Rich Loeb, WA3SOV noticed this item and sent the following message explaining how the unit is used:
Dave -
Hi, I saw your excellent web site with various code practice oscillators. I was shocked,
amazed and delighted to see that you have a picture of a Lafayette Radio Electronics
wireless code practice oscillator (I think the model number was 99-26080). On your web
site, you asked: "Can anyone describe how this oscillator was used?" Well, I
can, because I owned one, and used it to learn the code.
First, it was made by Lafayette Radio Electronics (or at least one of their suppliers). It
was cheap. I think I paid between $5-8 for it in late 1971. This included a cheap, but
usable morse code key. The oscillator generated a frequency tone at the lower end of the
AM band (around 570 khz). You took a transistor radio, placed it near the oscillator, and
practiced sending code. The big advantage to the Lafayette oscillator was that you did not
need a separate speaker because the transistor radio already had one (the speaker was the
biggest cost to most of the code practice oscillators in those days).
The oscillator used a single 9-volt battery for power. The tone produced wasn't exactly
pure, but it was good enough. Also, placed close to a radio, the tone was high-pitched
enough that it didn't really matter. That oscillator got me up to 20 wpm. I think I gave
it away to an aspiring novice sometime in 1972.
I hope this fills in the history of this unique and cost-effective unit.
73,
Rich Loeb, WA3SOV