O A R C stands for Ottumwa Amateur Radio Club. In an effort to get more involvement in the club's activity, Terry, WA0ITP, started some building projects for club members to work on during club meetings. One of those projects is an 80 M transmitter which he invisioned would be used in a slow speed cw net for members or anyone else wishing to participate. He designed the OARC-80 transmitter which puts out about 1 watt on 3686.4 KHz. This is plenty of power to be heard in and around Ottumwa. I live about 12 miles from Ottumwa (in Batavia) and have no trouble hearing and being heard. Terry furnished all the parts and manhattan board to all the club members and helped all of us with construction.
Below are pictures of the one I built. I think everyone used an Altoids tin for the box.
Terry and I decided to put a keyer chip in ours. The chips are from KD1JV. Steve calls it the simple keyer chip.
I put mine on a little board along with an audio amp to help drive the transducer.
Below are 3 pictures of the keyer chip inside the altoids box.