IRV
The Chater Report said that she tried the RDF on the plane's test flight by attempting to pick up the Lae station and was unable to get a null. When she landed she said that she "assumed" that the reason was that she was too close to the antenna (Lae antenna). She took off next AM.
As I always say when I mention this point, either the RDF wasn't working properly or she wasn't operating it properly. Either way, when the successful completion of the leg depends on the RDF, you don't takeoff without knowing absolutely that it works, no assumptions. She took off without knowing.
I am not aware of any radio transmissions in which she mentions that she was attempting to acquire the Itasca's RDF beacon. Quite the contrary, she asked for the Itasca to take a bearing on her. And the equipment she had on board wasn't capable of sending a signal at a frequency that the Itasca could aquire and follow as she flew.
What could she have done?
1. During the test flight,Tuned the RDF into another station (Rabaul, perhaps) to see if the RDF worked ok. If it worked, ok. If it didn't work, then FIX IT before taking off.
2. After takeoff, tuned the RDF to the Lae station as she flew away to see if the RDF was working. If it worked, ok. If not, turn back and FIX IT.