The addition of the 10 K resistor was not absolutely necessary, but it did result in better audio, so I kept it in.
It is a strange radio. To tune it, you use the loopstick, and fine tune it (or tune out interfering stations) with the variable capacitor. It works, but you do need a long wire antenna and ground. It is basically a crystal radio with an amplifier. It is hard to eliminate a local station, but it does eventually reduce it enough so other stations are easily heard.