TIGHAR

Amelia Earhart Search Forum => Radio Reflections => Topic started by: Terry Richard on April 04, 2011, 05:20:10 PM

Title: Electra radio equipment and antennas
Post by: Terry Richard on April 04, 2011, 05:20:10 PM
I read the TIGHAR article on the Electra radios:

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm

It was a pretty good read, but the book "The Sound of Wings" by Mary Lovell claims that while the Electra was in Miami, the service techs there discovered the problems with Joseph H. Gurr's work, and undid most of it. Specifically, they undid the antenna lengthening.

Also, it is claimed in that book that Bendix persuaded Amelia to replace all of the Western Electric equipment with Bendix.

It would be nice to be able to definitively find out what was aboard, and what the story on the antennas was.

Terry
Title: Re: Electra radio equipment and antennas
Post by: Bruce Thomas on April 04, 2011, 05:44:01 PM
I think I recall reading that info about the work done at Miami is indeed less than what would be desired.  I suggest you will want to read the Ameliapedia article entitled "Modifications by Joe Gurr," (http://tighar.org/wiki/Gurr) if you haven't already done so.
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on April 04, 2011, 06:09:31 PM
It was a pretty good read, but the book "The Sound of Wings" by Mary Lovell claims that while the Electra was in Miami, the service techs there discovered the problems with Joseph H. Gurr's work, and undid most of it. Specifically, they undid the antenna lengthening.

Also, it is claimed in that book that Bendix persuaded Amelia to replace all of the Western Electric equipment with Bendix.

It would be nice to be able to definitively find out what was aboard, and what the story on the antennas was.

Let's start by examining Lovell's sources.

Can you list them here?

Did her informants document these claims?

Where are those documents today?

Can we examine those documents?

Are the documents from 1937?  From the people who did the work?  From someone else?  How credible are the witnesses?
Title: Re: Electra radio equipment and antennas
Post by: Terry Richard on April 05, 2011, 08:07:34 AM
I wasn't trying to stir up a hornets' nest here, just asking the questions. I'm not trying to dispute anything that I read on TIGHAR, just that there has been lots of contradictory stuff written about Amelia Earhart's disappearance, and some of it just leaves me befuddled and bewildered. That is the intent of my posts, to clear up the mystery.

Lovell's sources:

Some of what she states is from Elgen Long. I haven't read his book yet, it's on the way. She states in her book, "The Sound of Wings" (from which I quote) that he (Long) interviewed a former Bendix employee, who stated that before Amelia left Miami she was persuaded by Bendix to discard the Western Electric equipment for the new Benidix RA-1 series.

"Bendix offered Amelia five thousand dollars to ditch the Western Electric gear," Elgen Long told me.

Elgen Long also stated that he has further proof of this via Stan Rose, the mechanic who checked Amelia's radio and DF equipment at Darwin and who replaced the blown fuse. Rose apparently stated that all the radio equipment was Bendix.

The Herald Tribune reported on May 30, 1937 that, having tried unsuccessfully to raise a local radio station on both 3105 and 6120 kilocycles, the Pan Am technicians inspected the system and decided that the problem lay "with the new antennae recently installed on the flying laboratory". They believed it to be of an improper length to give the transmitter its maximum efficiency and range and "set to work this afternoon experimenting with various lengths and hope to have the problem solved in time for another test flight tomorrow".

Later, George (Putnam) was to advise Paul Mantz that the radio had given endless trouble. "As I understand it... the technicians decided... that the longer aerials were improper. One part of them just canceled out the other, so they shortened the aerials and got the thing pretty well licked..."

Terry
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on April 05, 2011, 12:30:25 PM
I wasn't trying to stir up a hornets' nest here, just asking the questions. I'm not trying to dispute anything that I read on TIGHAR, just that there has been lots of contradictory stuff written about Amelia Earhart's disappearance, and some of it just leaves me befuddled and bewildered. That is the intent of my posts, to clear up the mystery.

If you want to "clear up the mystery," you need primary sources to do so: documents from at or near the time of the events in question.

Quote
Lovell's sources:

Some of what she states is from Elgen Long. I haven't read his book yet, it's on the way. She states in her book, "The Sound of Wings" (from which I quote) that he (Long) interviewed a former Bendix employee, who stated that before Amelia left Miami she was persuaded by Bendix to discard the Western Electric equipment for the new Benidix RA-1 series.

"Bendix offered Amelia five thousand dollars to ditch the Western Electric gear," Elgen Long told me.

Elgen Long also stated that he has further proof of this via Stan Rose, the mechanic who checked Amelia's radio and DF equipment at Darwin and who replaced the blown fuse. Rose apparently stated that all the radio equipment was Bendix.

May we check Stan's letters and diaries?

The plane did have a Bendix radio direction finder coupler (http://tighar.org/wiki/Radio_equipment_on_NR16020#Bendix_direction_finding_coupler).

Quote
The Herald Tribune reported on May 30, 1937 that, having tried unsuccessfully to raise a local radio station on both 3105 and 6120 kilocycles, the Pan Am technicians inspected the system and decided that the problem lay "with the new antennae recently installed on the flying laboratory". They believed it to be of an improper length to give the transmitter its maximum efficiency and range and "set to work this afternoon experimenting with various lengths and hope to have the problem solved in time for another test flight tomorrow".

Later, George (Putnam) was to advise Paul Mantz that the radio had given endless trouble. "As I understand it... the technicians decided... that the longer aerials were improper. One part of them just canceled out the other, so they shortened the aerials and got the thing pretty well licked..."

This has been discussed at great length in the old Forum.  If you can come up with something stronger than "Elegen Long says," that will help to resolve the controversy.
Title: Re: Electra radio equipment and antennas
Post by: h.a.c. van asten on May 13, 2011, 02:45:46 AM
Moleski. With the high power input of Earhart´s transmitter it is hardly possible to expect any representative propagation malfunction , especially when in the Howland region , the on board radio radiated signals excellently , whereas reception of Itasca´s signals was confirmed. When the DR-Celestial approach showed failure , DF operations changed from second to first line priority , for which A/c´s crew was not instantly capable. Mindful of Occam´s razor , the Earhart tranmissions ended since from 1,000 ft altitude a Lockheed Electra (being generically nose heavy) used less than 15 seconds to get down with  engine(s) lost , if still the more or less under pilot´s control. 
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on May 13, 2011, 05:34:59 AM
Moleski. With the high power input of Earhart´s transmitter it is hardly possible to expect any representative propagation malfunction , especially when in the Howland region , the on board radio radiated signals excellently , whereas reception of Itasca´s signals was confirmed.

The Electra was not heard on AE's daytime frequency for four hours after takeoff from Lae. (http://tighar.org/wiki/Transmission_timeline)  That suggests to me that there was something peculiar about her transmitter.  I understand that you do not agree with this interpretation of the data.

Quote
When the DR-Celestial approach showed failure , DF operations changed from second to first line priority , for which A/c´s crew was not instantly capable. Mindful of Occam´s razor , the Earhart tranmissions ended since from 1,000 ft altitude a Lockheed Electra (being generically nose heavy) used less than 15 seconds to get down with  engine(s) lost , if still the more or less under pilot´s control. 

OK.  That guess certainly explains the failure to hear any more transmissions after 2013 GMT.  You may be right.  You clearly should be working with the splashed-and-sank groups. (http://tighar.org/wiki/Alternative_theories#Splashed-and-Sank)  TIGHAR believes that some of the post-loss radio messages (http://tighar.org/wiki/PLRM) are credible.  This means that the simplest explanation (they crashed 15 seconds after the final transmission) doesn't cover all of the data; something other than a splashdown at sea must account for the end of the transmissions.  For me, it was the decision to change to the daytime frequency (http://tighar.org/wiki/Last_words) that caused the end of transmissions.

"Due to the skip characteristics of 6210 Kilocycles, Earhart’s decision to switch to that frequency effectively shuts off any further reception by Itasca.  Conclusion: The Coast Guard’s official position that the Earhart flight ran out of fuel and crashed at sea shortly after the final transmission heard by the Itasca is not supported by the facts" ("Log Jam," TIGHAR Tracks 12:2-3, 1996 (http://tighar.org/Publications/TTracks/12_2/logjam.html)).
Title: Re: Electra radio equipment and antennas
Post by: h.a.c. van asten on May 13, 2011, 12:32:14 PM
T.Rchd  With the o/b of A/c powerful transmitter it is not very important what type of antenna on the plane was in use : evidently the installation worked when in the Howland region and RDF failure became apparent , only after the DR-Astro precomputations failed to the effect that the island did not run in sight. The before 1912 GMT bearings asked for , were most probably to support the Astro-DR approach which had been set in from sunrise o/b of A/c. This does not mean that radio communications research is useless : such investigations may serve the heuristic aim (´we just want to know it´).
Title: Re: Electra radio equipment and antennas
Post by: h.a.c. van asten on May 22, 2011, 12:55:02 AM
Moles. It may be so that some of the post loss signals are credible , but are they more credible than Earhart´s own : at 1912 GMT "1/2 hour fuel left" ?  For the discrepancy , it is not necessary to belong to any group , " splash-sank" or not . A complex incident like this can , from a certain level , not be solved by verbal determination. There is however , a chance that a solution can be found by quantitative outcomes of a good navigation model , and within the limits of the science and practice of navigation of the era. It is , of course , TIGHAR´s own choice but : if you continuously debate about one single option , a forum will in the course of time become an everlasting repetition without any new vistas , reality itself delivering the evidence : scores of books , titled "Problem Solved" have in the course of time passed in review , each one with it´s own dogma , raised or not to a religion , and with no problem solution at all.
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on May 22, 2011, 06:25:18 AM
Moles. It may be so that some of the post loss signals are credible , but are they more credible than Earhart´s own : at 1912 GMT "1/2 hour fuel left" ?

Yes.  Randy Jacobson dealt with this alleged transmission in "The 1937 Search: The First 24 Hours." (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/first24hours.html)

Quote
For the discrepancy , it is not necessary to belong to any group , " splash-sank" or not . A complex incident like this can , from a certain level , not be solved by verbal determination.

You just used a "verbal determination" to call "verbal determinations" into question.  

Words (Latin, verba, the root of the word "verbal") are pretty much all we've got to work with in presenting arguments in this forum.  If you are claiming non-verbal (i.e., mystical) knowledge of reality, then there is no need for you to share any more verbal determinations with us.  If your argument can't be put into words, then it doesn't belong in a Forum that is nothing but a collection of words.

Quote
There is however , a chance that a solution can be found by quantitative outcomes of a good navigation model , and within the limits of the science and practice of navigation of the era.

Do you mean something like Randy Jacobson's Monte Carlo simulation (http://tighar.org/wiki/Monte_carlo)?

Your "quantitative outcomes" are based on assumptions whose worth has been challenged by those who are well qualified to do so.  Your assumptions are not self-evident nor are they demonstrated from self-evident axioms.  They are all hypotheses in need of historical evidence.   After you make YOUR assumptions, then, of course, it is a relatively trivial matter to do the calculations that would lead to a different area to search rather than Niku.  The magic is not in the mathematics but in the adoption of your starting-points:


... THEN we can calculate that they did not land safely on Niku.

Quote
It is , of course , TIGHAR´s own choice but : if you continuously debate about one single option , a forum will in the course of time become an everlasting repetition without any new vistas , reality itself delivering the evidence : scores of books , titled "Problem Solved" have in the course of time passed in review , each one with its own dogma , raised or not to a religion , and with no problem solution at all.

TIGHAR is not responsible for things published by other groups.  If you dislike what other researches have written, please go share your non-verbal determinations with them in their publicly accessible forums.
Title: Re: Electra radio equipment and antennas
Post by: Bill Lloyd on May 22, 2011, 10:37:57 AM
Moles. It may be so that some of the post loss signals are credible , but are they more credible than Earhart´s own : at 1912 GMT "1/2 hour fuel left" ?  For the discrepancy , it is not necessary to belong to any group , " splash-sank" or not . A complex incident like this can , from a certain level , not be solved by verbal determination. There is however , a chance that a solution can be found by quantitative outcomes of a good navigation model , and within the limits of the science and practice of navigation of the era. It is , of course , TIGHAR´s own choice but : if you continuously debate about one single option , a forum will in the course of time become an everlasting repetition without any new vistas , reality itself delivering the evidence : scores of books , titled "Problem Solved" have in the course of time passed in review , each one with it´s own dogma , raised or not to a religion , and with no problem solution at all.
I have attempted to read and understand the numerous posts that you have made in the forum. To be competley honest, I find it extremely difficult to follow your logic in the various threads and to provide any meaningful response. Your comments that the Earhart incident cannot be solved by verbal determination is, of course, correct, however, to my knowledge it has never been stated that is what this forum is about.

TIGHAR has researched and presented much evidence and has stated that the scientific method is used to evaluate that evidence. The relevance of that evidence is what is normally debated.  I see no evidence that this forum continuously debates about "one single option", conversely many options are argued and reargued.

With all due respect, I would suggest that you take time and read as much of the old forum and published documents as possible before you post on a subject. Make an attempt to synthesize that information before you express an opinion or propose a theory. I would also suggest that you construct your sentences with better verbiage, usage and punctuation so that  they can be more easily read and understood. Most of your writings appear rambling and incoherent and could  be the reason that you do not get meaningful responses. Do not make conclusory statements (http://www.houston-opinions.com/law-conclusory-affidavit-statement.html) (construed (http://www.tnwd.uscourts.gov/JudgeBryant/opinions/558.pdf)) and be prepared to support your arguments with appropriate authorities. Provide links to those authorities so that readers may see them.
Title: Re: Electra radio equipment and antennas
Post by: Mark A. Cook on June 02, 2011, 07:23:41 PM
I am a Newbie here Mr. Lloyd.. with only  3 + hours just reading this forum..

I don't have enough time to say much but I do see your all have a mountain of very good infromation on here.. The most I ever seen on this case in question..We talking about close to 74 years if not more time has passed... A long time for any first hand fresh accounts on anything today..

Myself I plan on reading a whole lot more before I make up my mind on much at all that happened ..  I think that is a very wise tip on what to do..
Title: Re: Electra radio equipment and antennas
Post by: Tony on June 04, 2011, 06:44:19 AM
Sorry if this is old news and already discussed but I thought I might bring it to the attention of the forum in case some of it is new.

 There is mention of Radio equipment being serviced by a Sgt Stan Rose of the RAAF Directional Finding Station at Darwin in this article dated 28 July 1937...has anybody seen the report I wonder?

http://trove.nla.gov.au/ndp/del/article/30763161?searchTerm=%22amelia%20earhart%22%20darwin&searchLimits=sortby=dateAsc

And interestingly there is film footage of the Lae take off taken by Engineer and Aviator Syd Marshall who later become a collector of rare planes.

http://trove.nla.gov.au/ndp/del/article/51274550?searchTerm=%22amelia%20earhart%22%20darwin&searchLimits=sortby=dateAsc

Tony
Title: Re: Electra radio equipment and antennas
Post by: William G Torgerson on June 04, 2011, 07:06:16 PM
T.Rchd  With the o/b of A/c powerful transmitter it is not very important what type of antenna on the plane was in use : evidently the installation worked when in the Howland region and RDF failure became apparent , only after the DR-Astro precomputations failed to the effect that the island did not run in sight. The before 1912 GMT bearings asked for , were most probably to support the Astro-DR approach which had been set in from sunrise o/b of A/c. This does not mean that radio communications research is useless : such investigations may serve the heuristic aim (´we just want to know it´).

A word of caution here .... the transmitter's power is not the only variable.  50 watts might sound like a lot, but on A3 (AM Modulation) most of that is wasted in the sidebands. What really matters is the A/C's ERP (Effective Radiated Power) and that can be a small fraction of the input power.  It (the ERP) can be very directional also.  I once worked on an Naval Aircraft (A3D-2) HF AM system (AN/ARC-38 w/CU-509 Automatic Antenna Coupler) that generated 100 watts of input to the antenna (which was only 11.5 feet in length) but had an ERP of about 3 watts .... directed mainly to the front of the A/C. These were at frequencies close to 41 meters (not too far from 6210 kHz).  The system could be made to work, but you had to be aware of its limitations.

Bill Torgerson
Title: Re: Electra radio equipment and antennas
Post by: Jon Romig on September 06, 2013, 06:14:12 PM

"Due to the skip characteristics of 6210 Kilocycles, Earhart’s decision to switch to that frequency effectively shuts off any further reception by Itasca.  Conclusion: The Coast Guard’s official position that the Earhart flight ran out of fuel and crashed at sea shortly after the final transmission heard by the Itasca is not supported by the facts" ("Log Jam," TIGHAR Tracks 12:2-3, 1996 (http://tighar.org/Publications/TTracks/12_2/logjam.html)).

Hi Marty,

I have not been able to find a discussion of the skip problem with 6210 kilocycle transmissions. Could you point me in the right direction?

Thanks!

Jon
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on September 06, 2013, 06:24:10 PM
I have not been able to find a discussion of the skip problem with 6210 kilocycle transmissions. Could you point me in the right direction?

There are a few thoughts and links in the article on "Radio propagation." (http://tighar.org/wiki/Radio_propagation)

Title: Re: Electra radio equipment and antennas
Post by: Gary L Kerr on September 14, 2013, 05:17:39 PM
Ken brought up a very interesting point in 2010:

Considering that 1937 was about the height of that solar cycle for radio propagation and that the transmitter was right adjacent to salt water (a great reflector), it's certainly possible that these signals were heard in the US and elsewhere.

You can see a graph of past solar cycles here.  Look for the "Monthly  Sunspot Numbers 1900-1999" graph.  The higher the sunspot number, the better for radio wave propagation.  http://www.wm7d.net/hamradio/solar/historical.shtml
Title: Re: Electra radio equipment and antennas
Post by: Doug Ledlie on May 12, 2014, 08:53:40 PM
Another hibernating thread resurrected...

Have been trying to educate myself regarding Vee antennas and have found some discussion around the web that they can be significantly "directional" in certain configurations ie significantly better performance opposite the vertex.

Some talk confirming directional characteristics of the Electra dorsal vee here:
http://tighar.org/wiki/Dorsal_antenna#cite_note-6
but I didn't find anything more in depth.

So, any radio experts know if the electra vee antenna directionality could be estimated with any accuracy.
Title: Re: Electra radio equipment and antennas
Post by: Tim Gard on May 12, 2014, 09:34:04 PM
Another hibernating thread resurrected...

Have been trying to educate myself regarding Vee antennas and have found some discussion around the web that they can be significantly "directional" in certain configurations ie significantly better performance opposite the vertex.

Some talk confirming directional characteristics of the Electra dorsal vee here:
http://tighar.org/wiki/Dorsal_antenna#cite_note-6
but I didn't find anything more in depth.

So, any radio experts know if the electra vee antenna directionality could be estimated with any accuracy.

I found this to be very rewarding ...

https://www.youtube.com/watch?v=IqS9GXM7nag

The videos are a very quick way of grasping the hypothesis details ...

https://www.youtube.com/user/TIGHARchannel

Click on the word "videos" next to home to have the full list displayed.
Title: Re: Electra radio equipment and antennas
Post by: Doug Ledlie on May 13, 2014, 05:54:03 AM
Thanks Tim, good info

I had seen some discussion before about signal "donuts" (mmmm...now I'm going to be drooling on my shirt all morning)

Was wondering though specifically about pure transmit directionality possibilities ie maybe the Electra configuration provided 2 watts ahead, 1 watt sideways and 20 watts behind or 20 watts ahead and 2 watts behind etc - those are totally random numbers btw not suggesting those are the actual numbers or even proper terminology.

Ultimately wondering how the antenna being on a different plane (thats plane in the vertical/horizontal sense) when parked vs in flight, 10E being a tail dragger, would impact transmission possibilities.  Haven't found that point discussed and maybe its irrelevant, dunno
Title: Re: Electra radio equipment and antennas
Post by: Tim Gard on May 17, 2014, 02:13:05 AM
Was wondering though specifically about pure transmit directionality possibilities ie maybe the Electra configuration provided 2 watts ahead, 1 watt sideways and 20 watts behind or 20 watts ahead and 2 watts behind etc - those are totally random numbers btw not suggesting those are the actual numbers or even proper terminology.

I've forgotten where I acquired the info, but somebody modified Amelia's antenna, if not her ATU, to try to improve support for a wider range of frequencies.

The result was not as successful as planned and I think 6210 KHZ suffered by the mod.

Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on May 17, 2014, 05:18:59 AM
... somebody modified Amelia's antenna, if not her ATU, to try to improve support for a wider range of frequencies.

The result was not as successful as planned and I think 6210 KHZ suffered by the mod.

"NR16020 antennas." (http://tighar.org/wiki/Antennas)
Title: Re: Electra radio equipment and antennas
Post by: Tim Gard on May 17, 2014, 07:36:46 PM
"NR16020 antennas." (http://tighar.org/wiki/Antennas)

Thanks Martin.

Title: Re: Electra radio equipment and antennas
Post by: Neff Jacobs on March 02, 2015, 05:20:44 PM
I ran across an article from the December 1942 Electronics Magazine by  Paul Holmes Chief Engineer of Stoddart Aircraft Radio Company.

According to Holmes the practical length of an Off Center Fed V includes the length of the fed line and from the feed point to the long end of the V.  Holmes ignores the short end of the V  Each leg scales 25.4 feet long on the Long illustration of the L10.   The feed point appears to be at 5.25 feet from center as does the length of the feeder as applied at Miami.  It comes to 35.5 feet.  If the wire was in free space it would resonate at 6931kc.   According to Holmes Nomograph  featured in the article more like 6200kc.   6210 would be a good guess.   The nice thing about the off center fed V is you can change it's resonate frequency by changing  the feed point.   A Mininec model of the antenna appears to be a short top loaded vertical.   Most of the radiation is vertically polarized.  The V acts much more as a capacity hat and does not radiate to a significant degree.
Neff
Title: Re: Electra radio equipment and antennas
Post by: Eddie Rose on March 05, 2015, 02:41:46 PM
Before the last flight, how many times in her flying career had Amelia used the radio direction finder unit successfully to find a destination?
Title: Re: Electra radio equipment and antennas
Post by: Ric Gillespie on March 05, 2015, 03:04:56 PM
Before the last flight, how many times in her flying career had Amelia used the radio direction finder unit successfully to find a destination?

Never.  Even the test she did at Lae the day before she left for Howland failed.
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on March 05, 2015, 03:13:17 PM
Before the last flight, how many times in her flying career had Amelia used the radio direction finder unit successfully to find a destination?

I'm going to put my money on "zero."

It's hard to prove a negative (not impossible, just difficult).

I'm emphasizing "Amelia" in your question.

If RDF was used in the first leg of the first round-the-world attempt, as seems likely to me, it wasn't Amelia at the controls; Mantz and Manning took seven bearings (http://tighar.org/wiki/Rdf#Previous_procedure_.28Oakland_to_Honolulu.29). 

Of course, we don't have complete records of every flight AE took in the Electra after the cockpit was re-configured to put her in charge of RDF.  So the correct answer might be greater than zero.  But in such test flights, I imagine they had other means of getting back home.  My impression is that the first time she was dependent on RDF to "find a destination" was on the flight from Lae to Howland.
Title: Re: Electra radio equipment and antennas
Post by: Ric Gillespie on March 05, 2015, 04:50:31 PM
Of course, we don't have complete records of every flight AE took in the Electra after the cockpit was re-configured to put her in charge of RDF.

How was the cockpit re-configured?
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on March 05, 2015, 05:03:49 PM
Of course, we don't have complete records of every flight AE took in the Electra after the cockpit was re-configured to put her in charge of RDF.

How was the cockpit re-configured?

OK.  I must have gotten confused with the removal of the Hooven control head, for which there are TIGHAR documents, and the location of the remote control heads for the transmitter and receiver:

Michael Everette, "Technical Analysis" (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm#12)

"Channel shifting was accomplished by means of a multi-gang switch to select crystals and tuned circuits for each channel. The switch was activated from a crank on a remote control head located in the cockpit, linked to the transmitter through a flexible tach-shaft resembling an automotive speedometer cable."

"The Model 20B receiver was a remote-control model, with tuning dial, band switch, volume control and other controls located in a Model 27A remote control head linked to the receiver by means of tach-shafts. The remote head was mounted in a center console below the instrument panel in NR16020; the receiver itself was mounted beneath the right seat in the cockpit."

I thought that some of these controls were at the navigator's station and then were moved to the cockpit after the first attempt.  The transmitter was below the navigator's table (Ric Gillespie (https://tighar.org/wiki/Ric_Gillespie), 2 March 2009  Forum (https://tighar.org/wiki/AESF).)

OK, took a while, but I found the info I've been looking for.  It's in a post from Ric Gillespie, 20 November 2014, Forum. (http://tighar.org/smf/index.php/topic,1553.msg35123.html#msg35123) I had thought that the frequency control switches were over on AE's side of the cockpit, but manifestly, that is not the case.


Title: Re: Electra radio equipment and antennas
Post by: Ric Gillespie on March 05, 2015, 05:23:44 PM
The controls for the radio were moved to her side of the cockpit, I believe. 

I think my source is Ric Gillespie.

You KNOW you can't trust that guy.
As far as I know, we don't have a photo of the cockpit layout after Manning jumped ship and the plane was repaired following the Luke Field wreck.
Title: Re: Electra radio equipment and antennas
Post by: Martin X. Moleski, SJ on March 05, 2015, 05:55:03 PM
The controls for the radio were moved to her side of the cockpit, I believe. 

I think my source is Ric Gillespie.

You KNOW you can't trust that guy.
As far as I know, we don't have a photo of the cockpit layout after Manning jumped ship and the plane was repaired following the Luke Field wreck.

Not your fault.

I messed up.

Working from memory ...  :-[
Title: Re: Electra radio equipment and antennas
Post by: Neff Jacobs on March 05, 2015, 08:09:20 PM
You may look here http://news.nationalgeographic.com/news/2014/07/140727-amelia-earhart-history-flight-airplanes-adventure-explorer/   to read about how Earhart used radio on her Honolulu Oakland flight.   She also carried a simple to operate, a single needle pointed to the station automatically, radio compass  by Bill Lear  http://mlsandy.home.tsixroads.com/Corinth_MLSANDY/rt105.html   reads in part 

So he, Bill Lear, took the next logical step.
  He brought his direction finder to the Bureau of Air Commerce, which
  wanted to improve private flying as well as commercial aviation and which
  had been working on a radio compass for fifteen years without much
  success.  If Lear could get the bureau to endorse his radio compass, he
  figured he would have a better shot at reaching the roughly 7,500 private
  pilots in the country as well as the major airlines.  He convinced
  Director Eugene Vidal to commission the bureau to test his Learoscope to
  see if it would be of any value to the private pilot.  Vidal hired his
  friend Amelia Earhart, for $1 a year, to fly Lear's direction finder
  (slightly rebuilt according to bureau specfications) in her bright red
  Lockeed Vega primarily to determine its possibilities as an air
  navigation aid for private owners of aircraft." To draw Earhart as a test
  pilot was a promotional coup, for the aviatrix- the first woman to cross
  the Atlantic, one year after Charles E. Lindbergh- was a darling of the
  media.  Vidal asked her to make notes and observations to assist [the
  bureau] to perfect the instrument."
Neff
Title: Earhart and Lears RDF in 1935: clues to 1937?
Post by: John Wallace on March 06, 2015, 12:55:18 AM
Interestingly, Lear designed the rdf (which became the basis for what he installed in Earhart's Vega) for the MacRobertson International Air Race from London to Melbourne, Australia. This race covered much of the same ground Earhart later flew over in her round the world trip. 

Further info on Lear, 1935 rdf (including pics), and trip across the country to install in Earharts Vega can be found at:
http://www.dmairfield.com/people/lear_wm/index.html (http://www.dmairfield.com/people/lear_wm/index.html) 
and re the Vega itself with photos of the rdf loop:
http://www.parksfield.org/airplanes/NR965Y/ (http://www.parksfield.org/airplanes/NR965Y/)

Earhart herself commented on her experience with the Lear RDF in a telegram to Putnam which is reproduced at the Purdue archives:
http://e-archives.lib.purdue.edu/cdm/singleitem/collection/epurdue/id/184 (http://e-archives.lib.purdue.edu/cdm/singleitem/collection/epurdue/id/184)

(Purdue archives also have some other information about the Lear rdf in her one of her scrapbooks.)

One small correction: the rdf was not installed for the Hawaii to California to trip. Lear flew to California and installed it for the California to Mexico City flight (on which leg she probably did get lost.) The rdf did remain on the vega after the Mexico City to Newark flight. It can be seen in the Grand Canyon Airport photo later in 1935 after the flight to Newark. 

I myself have wondered if Earhart's experience with Lears RDF in 1935 led to overconfidence when testing the rdf in the Electra at Lae and then in the ill fated leg where she disappeared.  It has always been puzzling to me how she was all over the Cambridge gas analyzer and Noonan all over the time checks but seemingly out to lunch about the rdf.  Lear had every reason to make sure Earhart knew how to use his rdf in 1935.  Its prototype had been flown over Asia to Australia. Her own 1935 telegram (which bolsters contemporary news accounts) shows she had at least some experience with it. So maybe she got lulled by what she thought she knew rather than publicity crazy, fact poor lack of interest in details.

Interestingly too, the Stormy Genius biography of Lear gives additional context for what seems to be pretty intense competition over rdf development in 1935. (In other parts of book not quoted in the web account.) So Hooven's later account in his report really seems to miss key context both as to the state of the rdf and also Earhart's prior experience.  Of course when your star publicist goes missing never to be found, it is understandable that Lear never further promoted the Earhart connection to his rdf.

Title: Re: Earhart and Lears RDF in 1935: clues to 1937?
Post by: Martin X. Moleski, SJ on March 06, 2015, 02:51:52 AM
... seemingly out to lunch about the rdf.

In my opinion, FWIW, you may drop "seemingly" from your account.

I would say she was "demonstrably out to lunch." (http://tighar.org/wiki/Failure_to_communicate#Misunderstanding_of_equipment:_Amelia_Earhart)

Quote
So maybe she got lulled by what she thought she knew rather than publicity crazy, fact poor lack of interest in details.

That makes sense. 

Quote
Hooven's later account in his report really seems to miss key context both as to the state of the rdf and also Earhart's prior experience.  Of course when your star publicist goes missing never to be found, it is understandable that Lear never further promoted the Earhart connection to his rdf.

Why did she install Hooven's system first?  Who liked it?

Why did she uninstall it?  Who didn't like it?
Title: Re: Electra radio equipment and antennas
Post by: Monty Fowler on March 06, 2015, 06:47:21 AM
The only thing I can contribute about a possible reason  for ditching the RDF prior to her second attempt was that Amelia seemed positively obsessed with weight, as in, reducing it. Anything that, in her mind, would not "earn its keep" during the flight got the heave-ho, either before or during. And since she never bothered to get proficient in RDF, let alone the ground-level basics of Morse code, to her RDF wasn't "worth the weight."

The wretched irony of which is if she had left that "worthless" instrument in, we might not still be having conversations about what happened to her and Fred.

LTM,
Monty Fowler, TIGHAR No. 2189 ECR