View source for Failed direction finding test in Lae

:; [[Ric Gillespie]], ''[[Finding Amelia]]'', p. 74.

:: On July 1, before having the plane fueled for the flight to Howland, Amelia made a short test flight to confirm that everything was working. She was, at last, able to establish two-way voice communication with the ground, transmitting to Lae on her [[frequency|daytime frequency of 6210 kilocycles]] and receiving Balfour’s reply on Lae’s frequency of 6522 kilocycles. Balfour’s assessment of the aircraft’s transmitter was that the 'carrier wave on 6210 kc was very rough and I advised Miss Earhart to pitch her voice higher to overcome distortion caused by rough carrier wave, otherwise transmitter seemed to be working satisfactorily.' Earhart then asked him to send a 'long dash' while she attempted to take a bearing on the station, but this attempt to use her homing device was unsuccessful as well.  ...

:: During the test flight, Earhart found she could receive Lae’s signal, but the intensity of the sound did not change when she rotated the [[loop]]. In the terminology of the time, she could not '[[direction finding|get a minimum]],' and so could not get a bearing on the sending station. The problem was that although the radio receiver could pick up the signal and she could hear the tone in her headphones, the direction-finding aspect of the system could not respond to such a high frequency. Amelia, however, decided that the test had failed because the airplane was too close to the station and the signal was too strong.

:: It is not clear whether Balfour’s previous ground test of the receiver included taking a bearing using the direction finder, but it is known that he carried out his test on a signal of 500 kilocycles, a frequency well within the loop antenna’s 200 to 1500 kilocycle capability. In the flight test, Earhart tried to take a bearing on Lae’s 6522 kilocycle signal but could not get a minimum. Balfour accepted Earhart’s diagnosis of the problem, and so passed another opportunity to discover the flaw in her plan for finding Howland Island.

== References ==
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== Related articles ==
* [[Timeline of the second round-the-world attempt]].
* [[Radio chronology]].

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