I have the Conar pair also, which i picked up at a sale here

This discussion isn't complete without acknowledging the late great Glen Zook K9STH (SK) who, every time the Conar transmitter was mentioned, would chime in with "That transmitter will chirp even when stored in the attic of my garage!".  

Like most one-tube transmitters it ran the crystal pretty hard and the solution was to turn it into a MOPA, which is just what I did, with the programmable oscillator board becoming the oscillator stage.  If I recall a wiring change was required to allow the sweep tube to work as an amplifier,   lifting one end of an RF choke if I recall.    If you're of a certain age you might remember the "Joe and Judy" novice series that appeared 73 Magazine, where the Conar Twins were featured.

73, Bob W9RAN