I simply don’t believe the ship in the picture has anything to do with Erhart’s crash site.
I’ve been to her home town many times. Worked for an old family who ran a distribution business there.
There are lots of efforts to piece the crash together. Her plane did have a radio, trailing wire operation. She had a radio operator on board too.
Here are some records related:
https://tighar.org/wiki/Transmissions_heard_from_NR16020
Sounds like they used a mixture of AM phone and CW transmissions. That was the extent of the equipment of the day. AM phone is not good for weak signal conditions. CW is usually much much better, with weak signals.
Distance between stations and time of day makes a huge difference on High Frequency signals. (HF is not very high now.) They were operating using 3.1 mhz and 6.2 mhz frequencies.
you posted: “She had a radio operator on board too.” are you referring to her navigator, Fred Noonan, or an unknown 3d person on the flight? From all I’ve read, over the decades, she alone operated the radios from the cockpit. Noonan was separated from her in the rear of the plane. There were also reports that she had left the trailing antenna at Lae Field because of its weight and the length of the flight to Howland Island.