Elgen long footnoted the reference as follows-
"Message 8013/1320, March 13, 1937, from COMSFDIV To USS SHOSHONE and COMHWSEC. National achives San Bruno Ca."
I cannot find that in the Database, so not sure of content/text when Long states Earhart requested the High frequency finder. Long obviously believed Earhart requested it and I would like to read the text of that message.
Marty has posted the contents of that message. (Thanks Marty)
The message was sent on March 13, 1937. At that time AE is in Oakland preparing for the planned departure of her first world flight attempt on March 16 (they didn't get off until the 17th). Her technical adviser, Paul Mantz, has only recently figured out that Earhart's navigator, Harry Manning, although an accomplished nautical navigator, couldn't do celestial navigation from an airplane. On March 13 AE and GP announced that Fred Noonan would join the team.
The message in question is from the Commander of the Coast Guard's San Francisco Division to USCG Shoshone, then on station at Howland Island. The message says nothing about a high frequency direction finder. It does say that "Plane suggests direction finder be set up on island." "Plane" obviously refers to Earhart but she knows that the cutter is already at Howland so she can't be asking for equipment they don't already have with them. I hope you can see that when Elgen Long wrote, "In March, Earhart had requested that a high frequency radio direction-finder be set up on Howland Island." he was flat wrong.
Of course there is also the united press transcript of June 27 mentioning a High frequency direction finder installed on Howland capable of tracking Earhart's course based on her signal. This alone doesn't prove Earhart was aware of the DF, but it is a second reference along with Long's fore mentioned communication.
Hanzlick's June 27 press release from Itasca does say, in part, "high frequency radio direction finder installed yesterday Howland." For Earhart, on the other side of the dateline, the date was June 28. She's in Darwin, Australia. For her to know the contents of Hanzlick's press release she would have to read a UP newspaper story based on the message. Such a story can't appear in American papers until June 28 (June 29 for AE). On the morning of June 29 she and FN took off for Lae, New Guinea. That same day - June 28 for Itasca, June 29 for AE -
Itasca sent a message to her in Lae: "...Itasca direction finder frequency range 550 to 270 Kcs..." No mention of the high frequency DF on Howland.
It does show the Press knew about it, Adm. Richard Black knew about it, the coast guard knew of it because they were working it.
I think it fairly strong evidence in itself that Earhart knew of it.
The press knew about it, Black knew about it, the CG knew about it, but there is no evidence whatsoever that AE knew about it and no clear opportunity for her to know about it.
Unless Black kept it a secret from Earhart for purposes unknown, however even if Black kept it from Earhart her husband probably would have known from United Press reporters. It was his job to manage PR.
Black's communications with Earhart are well documented. He never mentioned it. Putnam could have found out about it from UP stories on July 28 - if the stories mentioned it - but I can't find any mention of the HFDF in the press stories before the flight. If Putnam did learn about it there is no record of him telling AE about it.
Those connections and communications along with Earhart's asking for RDF on her signal in flight is strong indication to me she was aware of it being available if needed.
There appears to be no evidence that the connections and communications you refer to ever happened.
As Rear Admiral Black worked with various departments of the government from equatorial islands to commerce, as well as various branches of this armed forces to supervise this flight, including the chief of naval operations, and Navy Admiral Leahy, I would say it is inaccurate to state the Navy was not involved in the operation.
The Navy was involved but, prior to the disappearance and search, its role was minor and peripheral.
The coast guard obviously had control but was working under the direction of a Navy officer consulting with the Navy and Coast Guard. So perhaps coast guard and Navy, to which Richard Black belonged should share partial blame for the poor planning and action.
Black was not, at that time, a Navy officer. He did not, in any way, belong to either the Coast Guard or the Navy.
Your misunderstanding of the relationship between the various personnel and agencies involved in supporting the Earhart's flight is rather complete. At the risk of sounding self-serving, I suggest you get a copy of my book "Finding Amelia - The True Story of the Earhart Disappearance."