Modifications by Joe Gurr - Revision history

Moleski at 18:00, 13 October 2009

2009-10-13T18:00:49Z

← Older revision		Revision as of 18:00, 13 October 2009
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	'''Joseph H. Gurr''' was born circa 1901 and died circa 1988(?). It seems likely that he married Marion E. Jacobsen in November of 1931;<ref>Collected from sahara346.wordpress.com/j/, a link that now seems to be dead.</ref> [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).		'''Joseph H. Gurr''' was born circa 1901 and died circa 1988 (?). It seems likely that he married Marion E. Jacobsen in November of 1931;<ref>Collected from sahara346.wordpress.com/j/, a link that now seems to be dead.</ref> [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).

	Gurr worked on Earhart's [[Radio equipment on NR16020\| radios]] and [[NR16020 antennas\| antennas]] before both round-the-world attempts.		Gurr worked on Earhart's [[Radio equipment on NR16020\| radios]] and [[NR16020 antennas\| antennas]] before both round-the-world attempts.

Moleski at 18:00, 13 October 2009

2009-10-13T18:00:13Z

← Older revision		Revision as of 18:00, 13 October 2009
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	== Discussion of the modifications ==		== Discussion of the modifications ==
	=== The material seems to be authentic ===		=== The material seems to be authentic ===
	;[[Ric Gillespie]], 22 July 1998 [http://www.tighar.org/forum/Highlights1_20/highlights2.html Forum.]		;[[Ric Gillespie]], 22 July 1998 [http://www.tighar.org/Projects/Earhart/forum/Highlights1_20/highlights2.html Forum.]
	:The Gurr letter is a typed document signed by Gurr dated May 3, 1982. The Q and A document consists of typed questions from Goerner (different type-face than Gurr's letter) with handwritten responses under them from Gurr. It is undated and unsigned but the handwriting resembles Gurr's signature on the letter. Both documents appear to be authentic.		:The Gurr letter is a typed document signed by Gurr dated May 3, 1982. The Q and A document consists of typed questions from Goerner (different type-face than Gurr's letter) with handwritten responses under them from Gurr. It is undated and unsigned but the handwriting resembles Gurr's signature on the letter. Both documents appear to be authentic.
	=== Belly antenna used for receiving ===		=== Belly antenna used for receiving ===
	;Vern Klein, 9 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]		;Vern Klein, 9 September 2000 [http://www.tighar.org/Projects/Earhart/forum/Highlights101_120/highlights104.html Forum.]

	:I guess we have to remember that what Joe Gurr had to say in his communications with Fred Goerner was all relative to the way the radio equipment was when he last knew of it in Burbank.		:I guess we have to remember that what Joe Gurr had to say in his communications with Fred Goerner was all relative to the way the radio equipment was when he last knew of it in Burbank.
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	=== Consequences of lengthening the [[dorsal antenna]] ===		=== Consequences of lengthening the [[dorsal antenna]] ===
	;[[Ric Gillespie]], 9 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]		;[[Ric Gillespie]], 9 September 2000 [http://www.tighar.org/Projects/Earhart/forum/Highlights101_120/highlights104.html Forum.]

	:It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the dorsal Vee antenna would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.		:It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the dorsal Vee antenna would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.

Moleski at 19:58, 12 October 2009

2009-10-12T19:58:25Z

← Older revision		Revision as of 19:58, 12 October 2009
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	==== Everette's objections ====		==== Everette's objections ====
	[[Mike Everette]] criticizes Gurr's account of the changes he made in the [[dorsal antenna]]:<ref>[[Mike Everette]], [http://~~www.~~tighar.org/Projects/Earhart/~~Bulletins~~/~~52_ElectraRadios~~/~~52_ElectraRadios~~.htm#8 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>		[[Mike Everette]] criticizes Gurr's account of the changes he made in the [[dorsal antenna]]:<ref>[[Mike Everette]], [http://tighar.org/Projects/Earhart/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm#8 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>
	* The antenna was lengthened from 46' to 54'--not 50%, as Gurr claimed.		* The antenna was lengthened from 46' to 54'--not 50%, as Gurr claimed.
	* 54' is not a resonant length for any of the transmissions frequencies (500 kcs, 3105 kcs, 6210 kcs).		* 54' is not a resonant length for any of the transmissions frequencies (500 kcs, 3105 kcs, 6210 kcs).
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	=== In fairness to Gurr ... ===		=== In fairness to Gurr ... ===

	"The alterations to the antenna system aboard NR16020, while well-intentioned, resulted in degraded performance of the transmitter. In fairness to Joseph Gurr, however, it must be remembered that Earhart was obsessed with saving weight and this was one main reason she left behind her trailing-wire antenna. Gurr was trying to help preserve her 500 KHz capability, to enable use of the only emergency frequency then available; but by lengthening the dorsal Vee antenna, he created other serious problems. His radio knowledge may have been more empirical than theoretical; therefore, he may not have realized the extent or cumulative effect of the problems created by his changes. This sort of empirical knowledge was typical of the times; but it was not adequate to deal with this situation."<ref>[[Mike Everette]], [http://~~www.~~tighar.org/Projects/Earhart/~~Bulletins~~/~~52_ElectraRadios~~/~~52_ElectraRadios~~.htm#19 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>		"The alterations to the antenna system aboard NR16020, while well-intentioned, resulted in degraded performance of the transmitter. In fairness to Joseph Gurr, however, it must be remembered that Earhart was obsessed with saving weight and this was one main reason she left behind her trailing-wire antenna. Gurr was trying to help preserve her 500 KHz capability, to enable use of the only emergency frequency then available; but by lengthening the dorsal Vee antenna, he created other serious problems. His radio knowledge may have been more empirical than theoretical; therefore, he may not have realized the extent or cumulative effect of the problems created by his changes. This sort of empirical knowledge was typical of the times; but it was not adequate to deal with this situation."<ref>[[Mike Everette]], [http://tighar.org/Projects/Earhart/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm#19 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>

	== Related articles ==		== Related articles ==

Moleski at 17:38, 7 October 2009

2009-10-07T17:38:03Z

Moleski: /* Consequences of lengthening the dorsal antenna */

2009-03-01T15:56:16Z

Consequences of lengthening the dorsal antenna

← Older revision		Revision as of 15:56, 1 March 2009
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	:It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the dorsal Vee antenna would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.		:It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the dorsal Vee antenna would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.

			=== In fairness to Gurr ... ===

			"The alterations to the antenna system aboard NR16020, while well-intentioned, resulted in degraded performance of the transmitter. In fairness to Joseph Gurr, however, it must be remembered that Earhart was obsessed with saving weight and this was one main reason she left behind her trailing-wire antenna. Gurr was trying to help preserve her 500 KHz capability, to enable use of the only emergency frequency then available; but by lengthening the dorsal Vee antenna, he created other serious problems. His radio knowledge may have been more empirical than theoretical; therefore, he may not have realized the extent or cumulative effect of the problems created by his changes. This sort of empirical knowledge was typical of the times; but it was not adequate to deal with this situation."<ref>[[Mike Everette]], [http://www.tighar.org/Projects/Earhart/Bulletins/52_ElectraRadios/52_ElectraRadios.htm#19 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>

	== Related articles ==		== Related articles ==

Moleski at 15:33, 28 February 2009

2009-02-28T15:33:40Z

← Older revision		Revision as of 15:33, 28 February 2009
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	:"While the airplane was being repaired at Lockheed, I took the opportunity to redesign the top antenna. This required a new stub mast on top of the fuselage, behind the cockpit, with a wire to each rudder, and a lead-in from one side to an insulator in the fuselage. The antenna looked similar as before, but now we had about 50% more wire. It made a great deal of difference in radiated energy. Also, because of the added wire, this top antenna now would be more effective on 500KH."		:"While the airplane was being repaired at Lockheed, I took the opportunity to redesign the top antenna. This required a new stub mast on top of the fuselage, behind the cockpit, with a wire to each rudder, and a lead-in from one side to an insulator in the fuselage. The antenna looked similar as before, but now we had about 50% more wire. It made a great deal of difference in radiated energy. Also, because of the added wire, this top antenna now would be more effective on 500KH."

			==== Everette's objections ====
			[[Mike Everette]] criticizes Gurr's account of the changes he made in the [[dorsal antenna]]:<ref>[[Mike Everette]], [http://www.tighar.org/Projects/Earhart/Bulletins/52_ElectraRadios/52_ElectraRadios.htm#8 A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020.]</ref>
			* The antenna was lengthened from 46' to 54'--not 50%, as Gurr claimed.
			* 54' is not a resonant length for any of the transmissions frequencies (500 kcs, 3105 kcs, 6210 kcs).
			* The change did not materially improve the effectiveness of the antenna in the 500 kcs range and probably degraded performance on the voice frequencies.

	=== New loading coil ===		=== New loading coil ===

Moleski at 15:47, 26 February 2009

2009-02-26T15:47:10Z

← Older revision		Revision as of 15:47, 26 February 2009
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	~~{{draft}}~~
	'''Joseph H. Gurr''' was born circa 1901 and died circa 1988(?). It seems likely that he married Marion E. Jacobsen in November of 1931;[http://sahara346.wordpress.com/j/] [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).		'''Joseph H. Gurr''' was born circa 1901 and died circa 1988(?). It seems likely that he married Marion E. Jacobsen in November of 1931;[http://sahara346.wordpress.com/j/] [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).

			Gurr worked on Earhart's [[Radio equipment on NR16020\| radios]] and [[NR16020 antennas\| antennas]] before both round-the-world attempts.

	== Career and qualifications ==		== Career and qualifications ==
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	:"The Electra was absolutely capable of putting out a radio signal whether on the surface of the water, or on a reef or island. ... AE could not receive because the V antenna for that was beneath the aircraft. He also said it was possible that Earhart signals might be heard in the U.S. and not be heard in the immediate Pacific area because of [[skip characteristics]]."		:"The Electra was absolutely capable of putting out a radio signal whether on the surface of the water, or on a reef or island. ... AE could not receive because the V antenna for that was beneath the aircraft. He also said it was possible that Earhart signals might be heard in the U.S. and not be heard in the immediate Pacific area because of [[skip characteristics]]."

	== ~~Evaluations~~ of the modifications ==		== Discussion of the modifications ==
			=== The material seems to be authentic ===
	Vern Klein, 9 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]		;[[Ric Gillespie]], 22 July 1998 [http://www.tighar.org/forum/Highlights1_20/highlights2.html Forum.]
			:The Gurr letter is a typed document signed by Gurr dated May 3, 1982. The Q and A document consists of typed questions from Goerner (different type-face than Gurr's letter) with handwritten responses under them from Gurr. It is undated and unsigned but the handwriting resembles Gurr's signature on the letter. Both documents appear to be authentic.
			=== Belly antenna used for receiving ===
			;Vern Klein, 9 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]

	:I guess we have to remember that what Joe Gurr had to say in his communications with Fred Goerner was all relative to the way the radio equipment was when he last knew of it in Burbank.		:I guess we have to remember that what Joe Gurr had to say in his communications with Fred Goerner was all relative to the way the radio equipment was when he last knew of it in Burbank.

	:Gurr describes his first encounter with the radio equipment on the Electra. He says they had just flown in from New York with the radio receiver not working and he had somehow been suggested as the person who could fix it. Amelia and Putnam were frantic that radio equipment installed by so prestigious an outfit as Bell Labs. had failed. It seems to me that would be the Western Electric receiver.

	:It took a while for him to find the receiver under the co-pilot’s seat. The antenna lead was laying there not connected. When Gurr connected the lead, the receiver came to life. In the eyes of Amelia and Palmer, he had performed a miracle. He points out that people with radio experience were not easy to find in those days.

	:Of course, Gurr talks some about improvising to give Amelia some 500 kc transmitting capability without using a trailing-wire antenna. Nobody used voice on 500 kc. It was regarded as strictly CW.		:Of course, Gurr talks some about improvising to give Amelia some 500 kc transmitting capability without using a trailing-wire antenna. Nobody used voice on 500 kc. It was regarded as strictly CW.

	:Gurr says he tried to catch Amelia long enough to get her checked out on the use of the radio equipment, especially the direction finder, but had little success. Harry Manning had the operation down quite well and they would have time to work with it en route.

	:"Harry and I covered such things as ambiguity of bearings and flying triangular courses in order to obtain a proper signal source direction." This suggests that there was no thought of a "sensing antenna" to resolve the ambiguity.

	:On a trial flight out to about 400 miles, Gurr operated the radio equipment while other checks of the aircraft were being done. Radio performance was not good at that distance but got better as they got closer on the way back.

	:"I was able to take bearings on broadcast stations using the belly antenna, and then switching over to the loop." Note that he says "switching over" not "switching in." I think he used the belly antenna only to get a station tuned in with that more efficient antenna, then "switched over" to the loop to take a bearing -- an ambiguous bearing except that he knew the station was up ahead, not behind.		:"I was able to take bearings on broadcast stations using the belly antenna, and then switching over to the loop." Note that he says "switching over" not "switching in." I think he used the belly antenna only to get a station tuned in with that more efficient antenna, then "switched over" to the loop to take a bearing -- an ambiguous bearing except that he knew the station was up ahead, not behind.
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	:To me, this suggests that the belly antenna was the receiving antenna and the "V" on top was the transmitting antenna. The T/R relay in the transmitter was not involved and the transmitter could have been heard by the receiver -- if it was not totally "blocked" by the strong signal.		:To me, this suggests that the belly antenna was the receiving antenna and the "V" on top was the transmitting antenna. The T/R relay in the transmitter was not involved and the transmitter could have been heard by the receiver -- if it was not totally "blocked" by the strong signal.

	~~From~~ [[Ric Gillespie]]:		;[[Ric Gillespie]]:

	:Good work Vern, and a strong argument for an antenna set up that matches the antenna loss at Lae with the problems encountered at Howland. ...		:Good work Vern, and a strong argument for an antenna set up that matches the antenna loss at Lae with the problems encountered at Howland. ...
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	:It looks, to me, increasingly like Earhart removed the [[Hooven Radio Compass]], which entailed a separate receiver and a sense antenna, and replaced it with the new Bendix loop and coupler which used the existing WE20B receiver and did not employ a sense antenna. The belly antenna was the receiving antenna. When it was [[The Lost Antenna\| lost on takeoff at Lae]], Earhart lost her ability to receive until the one brief moment when she "switched over" to the loop and heard the "A"s on 7500. She then switched back to the missing belly antenna and again heard nothing.		:It looks, to me, increasingly like Earhart removed the [[Hooven Radio Compass]], which entailed a separate receiver and a sense antenna, and replaced it with the new Bendix loop and coupler which used the existing WE20B receiver and did not employ a sense antenna. The belly antenna was the receiving antenna. When it was [[The Lost Antenna\| lost on takeoff at Lae]], Earhart lost her ability to receive until the one brief moment when she "switched over" to the loop and heard the "A"s on 7500. She then switched back to the missing belly antenna and again heard nothing.

	~~----~~		=== Consequences of lengthening the [[dorsal antenna]] ===
			;[[Ric Gillespie]], 9 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]
	~~''Details in letter to Goerner''~~

	~~May 1982 letter to Fred Goerner: "I improvised a loading coil and resonated~~ the ~~top antenna system."~~

	[[~~Ric Gillespie]], 22 July 1998~~ [~~http://www.tighar.org/forum/Highlights1_20/highlights2.html Forum.]~~
	The Gurr letter is a typed document signed by Gurr dated May 3, 1982. The Q and A document consists of typed questions from Goerner (different type-face than Gurr's letter) with handwritten responses under them from Gurr. It is undated and unsigned but the handwriting resembles Gurr's signature on the letter. Both documents appear to be authentic.

	~~It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the~~ dorsal ~~Vee~~ antenna ~~would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.~~

	~~About this time [Ric: late February/early March 1937 during preparations for the first World flight attempt~~] we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megaherz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in direction finding. While the direction finding loop was designed for the lower frequencies, I found i could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough. (29 June 2000 [http://www.tighar.org/forum/Highlights81_100/highlights94.html Forum.)]

	~~----~~

	[[~~Mike Everette~~]], 7 September 2000 [http://www.tighar.org/forum/Highlights101_120/highlights104.html Forum.]

	Joe Gurr could have very easily made the necessary mods to the radio to jumper the switch function and therefore keep the radio in "Phone" mode. But! Here is a reason why he would NOT have done so, and one that raises credibility issues.

	Gurr was trying to "help" AE (yeah, right)preserve her transmitting capability on 500 KHz, by reconfiguring the dorsal antenna to serve on 500 instead of using the much more efficient trailing wire. AE apparently wanted the trailing wire removed, and radio operation simplified, after Harry Manning bolted from the second flight attempt... Manning was to have been the radio operator, and one of his jobs would be to manually reel out and in the trailing wire (as well as to throw the antenna selector switch, located in the aft section).

	So, AE knew (we believe) that she needed to preserve the 500 KHz capability. In those days, 500, or "600-meters" (wave length) was the only emergency universally guarded by ships.... and she would be over water quite a bit.

	NOBODY used voice on 500! It was then, and continued so until the mid 90s when the regulation requiring ships to guard it was phased out, a CW frequency only. Even Joe Gurr would have known this. He would have come on very strong to AE, I think, about this and the necessity for keeping her CW key.

	~~No one monitoring 500 would have been listening for/expecting a voice signal on 500.~~

	~~HOWEVER, was AE so strongheaded that she disdained all Gurr’s (and others) expert advice? Could have been. Very likely. ("I don’t care...")~~

	~~If Joe Gurr had that key I for one would like to know what happened to it. What happened to Gurr’s estate? Did he have heirs? Or~~ was the ~~contents~~ of ~~his house trashed, like I saw happen to the stuff of a recently deceased old time Ham~~ in ~~Durham, NC last month? Wonder if~~ that ~~key has ever turned~~ up ~~at a Hamfest someplace? Wonder if the person who has it now is aware of its origin~~ and ~~significance (and value)?~~		:It was the opinion of an earlier TIGHAR-member researcher (who had extensive experience in avionics) that Gurr's lengthening of the dorsal Vee antenna would have really screwed up her ability to transmit effectively on 3105 and 6210 without giving her any real transmit capability on 500 kc.

	== Related articles ==		== Related articles ==
			* [[Frequency, wavelength, and antenna tuning]].
	* [[NR16020 antennas]].		* [[NR16020 antennas]].
	* [[Radio equipment on NR16020]].		* [[Radio equipment on NR16020]].

Moleski: /* Tested equipment in flight */

2009-02-26T05:59:09Z

Tested equipment in flight

← Older revision		Revision as of 05:59, 26 February 2009
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	:"My assignment was to operate the radio, take bearings, and make radio contacts with FCC range stations on 3105MH and later on 6210MH. We flew out for three hours. Next Harry Manning would give us compass heading for San Francisco. I had an opportunity to find out just how the radio equipment performed over greater distances. We were about 400 miles out and from this distance the radio performed poorly. As we got closer, things got better and I was able to contact FCC stations quite well, both ways. I was able to take bearings on broadcast stations using the belly sensing antenna, and switching over to the [[loop]]. We flew right over the middle of the Golden Gate Bridge and headed south to Burbank. I was satisfied that the radio worked as well as could be expected considering power available and not the best of antennas."		:"My assignment was to operate the radio, take bearings, and make radio contacts with FCC range stations on 3105MH and later on 6210MH. We flew out for three hours. Next Harry Manning would give us compass heading for San Francisco. I had an opportunity to find out just how the radio equipment performed over greater distances. We were about 400 miles out and from this distance the radio performed poorly. As we got closer, things got better and I was able to contact FCC stations quite well, both ways. I was able to take bearings on broadcast stations using the belly sensing antenna, and switching over to the [[loop]]. We flew right over the middle of the Golden Gate Bridge and headed south to Burbank. I was satisfied that the radio worked as well as could be expected considering power available and not the best of antennas."
	:::''~~The~~ loop mentioned by Gurr ~~was not~~ the external Bendix loop ~~but must have been an internal~~ loop ~~antenna for [[direction finding]].~~''		:::''Was the loop mentioned by Gurr the external Bendix loop? Date of change from Hooven Radio Compass to Bendix external loop?''

	== Modifications after [[Luke Field\| Luke Field crash]] ==		== Modifications after [[Luke Field\| Luke Field crash]] ==

Moleski: /* Saw Navy receiver installed? */

2009-02-26T05:57:49Z

Saw Navy receiver installed?

← Older revision		Revision as of 05:57, 26 February 2009
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	:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."		:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."

	:"The receiver was a six band job covering 1.5 to 15 MH. (150 to 15,000 KC) For me it was easy, but I'm afraid Amelia did not quite understand the how of it. Her final reply was 'we will have lots of time en route to learn all about it.' True--en route OAKLAND to LAE was certainly time enough to learn how to tune that very fine, and really simple receiver. ... I did not personally install the receiver. Lockheed did, with a certain amount of advisory help from me."		:"The original DF receiver was a 200-400 KC, plus 3105 and 6210 capability mounted under the copilots seat. It worked OK. Along about then, we received a box marked "NAVY" containing a beautiful multi-band receiver. I never knew the model number but was definitely impressed. ... The receiver was a six band job covering 1.5 to 15 MH. (150 to 15,000 KC) For me it was easy, but I'm afraid Amelia did not quite understand the how of it. Her final reply was 'we will have lots of time en route to learn all about it.' True--en route OAKLAND to LAE was certainly time enough to learn how to tune that very fine, and really simple receiver. ... I did not personally install the receiver. Lockheed did, with a certain amount of advisory help from me" (Gurr to [[Goerner]], 29 March 1988).

	===== Tested equipment in flight =====		===== Tested equipment in flight =====

Moleski: /* Installed Navy receiver? */

2009-02-26T05:51:46Z

Installed Navy receiver?

← Older revision		Revision as of 05:51, 26 February 2009
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	:"I left the trailing wire reel installed, and it could be used. In fact, on one of our test flights, I unreeled this antenna and tried to raise someone on 500 kHz without success. 500 kHz is a frequency used for emergency communication. Ships at sea monitor this frequency with automatic equipment, but the radio operator still has to react. My sea experience showed 500 kHz to be a poor performer unless you can put out a strong signal to trip the auto alarm over any real distance, especially in daytime when low [[radio propagation\|frequency propagation]] is poor, and it would be an advantage to be in busy shipping lanes. Amelia was sold and wanted the 500 kHz capability, and I gave it to her as efficiently as possible under the limited circumstances."		:"I left the trailing wire reel installed, and it could be used. In fact, on one of our test flights, I unreeled this antenna and tried to raise someone on 500 kHz without success. 500 kHz is a frequency used for emergency communication. Ships at sea monitor this frequency with automatic equipment, but the radio operator still has to react. My sea experience showed 500 kHz to be a poor performer unless you can put out a strong signal to trip the auto alarm over any real distance, especially in daytime when low [[radio propagation\|frequency propagation]] is poor, and it would be an advantage to be in busy shipping lanes. Amelia was sold and wanted the 500 kHz capability, and I gave it to her as efficiently as possible under the limited circumstances."

	===== ~~Installed~~ Navy receiver? =====		===== Saw Navy receiver installed? =====

	:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."		:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."

			:"The receiver was a six band job covering 1.5 to 15 MH. (150 to 15,000 KC) For me it was easy, but I'm afraid Amelia did not quite understand the how of it. Her final reply was 'we will have lots of time en route to learn all about it.' True--en route OAKLAND to LAE was certainly time enough to learn how to tune that very fine, and really simple receiver. ... I did not personally install the receiver. Lockheed did, with a certain amount of advisory help from me."

	===== Tested equipment in flight =====		===== Tested equipment in flight =====

← Older revision		Revision as of 17:38, 7 October 2009
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	'''Joseph H. Gurr''' was born circa 1901 and died circa 1988(?). It seems likely that he married Marion E. Jacobsen in November of 1931;~~[http://~~sahara346.wordpress.com/j/] [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).		'''Joseph H. Gurr''' was born circa 1901 and died circa 1988(?). It seems likely that he married Marion E. Jacobsen in November of 1931;<ref>Collected from sahara346.wordpress.com/j/, a link that now seems to be dead.</ref> [[Fred Goerner]]'s last letter to Gurr says, "Hope all is well with you and Marion" (20 March 1988).

	Gurr worked on Earhart's [[Radio equipment on NR16020\| radios]] and [[NR16020 antennas\| antennas]] before both round-the-world attempts.		Gurr worked on Earhart's [[Radio equipment on NR16020\| radios]] and [[NR16020 antennas\| antennas]] before both round-the-world attempts.
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	== Gurr's recollections about the modifications ==		== Gurr's recollections about the modifications ==
	=== 3 May 1982 letter to [[Goerner]] ===		=== 3 May 1982 letter to [[Goerner]] ===
	* Gurr says he was reluctant to talk about his involvement with the [[radio equipment on NR16020]]. "[[Goerner]] found my name in Lockheed's engineering file in 1969." Goerner interviewed Gurr on 19 January 1970, sent him some questions that Gurr answered in longhand, and corresponded with him several times in the 1980s; the last letter from Goerner to Gurr is dated 20 March 1988.~~''[~~ref needed to Smithsonian collection~~]''~~		* Gurr says he was reluctant to talk about his involvement with the [[radio equipment on NR16020]]. "[[Goerner]] found my name in Lockheed's engineering file in 1969." Goerner interviewed Gurr on 19 January 1970, sent him some questions that Gurr answered in longhand, and corresponded with him several times in the 1980s; the last letter from Goerner to Gurr is dated 20 March 1988.<ref>Ref needed to Smithsonian collection.</ref>

	==== Modifications prior to [[first attempt]] ====		==== Modifications prior to [[first attempt]] ====
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	:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."		:"About this time we received a box marked U.S. Navy, containing a fine multi-frequency receiver, covering frequencies up to 20 megahertz. I do not know who was responsible for this acquisition, nor where it came from. I was pleased, as now the plane was capable of covering larger segments of frequencies which could be useful in radio communication, and even in radio direction finding. While the direction finding loop was designed for the lower frequencies, I found I could get a fairly good null on AM Broadcast Stations up to 1500KH. I figured it would probably be useful even on 3105KH if the received signal was strong enough."

	:"The original DF receiver was a 200-400 KC, plus 3105 and 6210 capability mounted under the copilots seat. It worked OK. Along about then, we received a box marked "NAVY" containing a beautiful multi-band receiver. I never knew the model number but was definitely impressed. ... The receiver was a six band job covering 1.5 to 15 MH. (150 to 15,000 KC) For me it was easy, but I'm afraid Amelia did not quite understand the how of it. Her final reply was 'we will have lots of time en route to learn all about it.' True--en route OAKLAND to LAE was certainly time enough to learn how to tune that very fine, and really simple receiver. ... I did not personally install the receiver. Lockheed did, with a certain amount of advisory help from me" (Gurr to [[Goerner]], 29 March 1988).		:"The original DF receiver was a 200-400 KC, plus 3105 and 6210 capability mounted under the copilots seat. It worked OK. Along about then, we received a box marked "NAVY" containing a beautiful multi-band receiver. I never knew the model number but was definitely impressed. ... The receiver was a six band job covering 1.5 to 15 MH. (150 to 15,000 KC) For me it was easy, but I'm afraid Amelia did not quite understand the how of it. Her final reply was 'we will have lots of time en route to learn all about it.' True--en route OAKLAND to LAE was certainly time enough to learn how to tune that very fine, and really simple receiver. ... I did not personally install the receiver. Lockheed did, with a certain amount of advisory help from me."<ref>Gurr to [[Goerner]], 29 March 1988.</ref>

	===== Tested equipment in flight =====		===== Tested equipment in flight =====
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	Exceprts from [[Goerner]]'s interview with Gurr at his home in Los Altos, 19 January 1970.		Exceprts from [[Goerner]]'s interview with Gurr at his home in Los Altos, 19 January 1970.

	:Thirteen gas tanks total: six in the wings (394 gallons) and seven in the fuselage (804 gallons) for a total capacity of 1198 gallons. After the Honolulu flight, one 51-gallon tank was removed from the fuselage, leaving the total capacity at 1147 gallons. Goerner noted that this accords with the [[Chater Report]]. Gurr also talked about the the 100-gallon tank that carried 50 gallons of 100 octane gas for takeoff.		:Thirteen gas tanks total: six in the wings (394 gallons) and seven in the fuselage (804 gallons) for a total capacity of 1198 gallons. After the Honolulu flight, one 51-gallon tank was removed from the fuselage, leaving the total capacity at 1147 gallons. Goerner noted that this accords with the [[Chater\|Chater Report]]. Gurr also talked about the the 100-gallon tank that carried 50 gallons of 100 octane gas for takeoff.

	:"The Electra was absolutely capable of putting out a radio signal whether on the surface of the water, or on a reef or island. ... AE could not receive because the V antenna for that was beneath the aircraft. He also said it was possible that Earhart signals might be heard in the U.S. and not be heard in the immediate Pacific area because of [[skip characteristics]]."		:"The Electra was absolutely capable of putting out a radio signal whether on the surface of the water, or on a reef or island. ... AE could not receive because the V antenna for that was beneath the aircraft. He also said it was possible that Earhart signals might be heard in the U.S. and not be heard in the immediate Pacific area because of [[propagation\|skip characteristics]]."

	== Discussion of the modifications ==		== Discussion of the modifications ==
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	* [[NR16020 antennas]].		* [[NR16020 antennas]].
	* [[Radio equipment on NR16020]].		* [[Radio equipment on NR16020]].

			== References ==
			<references />

	<!-- Please leave this category marker at the bottom. You may add this article to other categories if you wish -->		<!-- Please leave this category marker at the bottom. You may add this article to other categories if you wish -->
	[[Category:Radio considerations]]		[[Category:Radio considerations]]