Amelia Earhart and radio propogation

[W1RKW]

An interesting piece on theories of the disappearance of Amelia Earhart and radio transmissioins and radio propogation.

http://www.foxnews.com/scitech/2012/06/01/previously-dismissed-radio-signals-were-credible-transmissions-from-earhart/

[kb3ouk]

This one is also an interesting read.
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/HarmonyandPower.htm

[W8VG]

This is really interesting stuff.  In the late 1960's when I was in Boy Scouts, we used to collect and recycle newsprint to support the local BSA troop.  Was in this little town on outskirts of Cincinnati. I was a "bundler" and used to tie bundles of paper and magazines.  An older widow lady in town passed away and the BSA was called by the family to collect a bunch of her old magazines--which turned out to be Life magazines from about 1936 to late 40's.  Bundles and bundles of them.  Nobody realized then how collectible they'd eventually become.  I was just smart enough to grab a couple as I helped bundle the rest.  One was from May 1937 and had a pictorial on the disappearance and efforts to find Amelia.  I still have it.  When N8YHY was restoring his old Pierson PR-15 few years back, I scanned a picture from the article to send him.  It is attached and shows two LA area hams who reported hearing KHAQQ after she was down.  Notice the nice Pierson set. 

73's
Geo, W8VG/6
RPV, California

[W1RKW]

That is an interesting read.  Certainly more detail than the general report above. 

What puzzles me is they say the ant was resonant at 3105KHz. I wonder how with a radiation efficiency of only 17.6. At 75m our ants are roughly 132ft at resonance. The Electra could not have been that long and its ant would have had to be longer at 3105Khz to be really resonant.  Did aircraft trail a wire while in flight?

This one is also an interesting read.
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/HarmonyandPower.htm

[k4kyv]

This is really interesting stuff.  In the late 1960's when I was in Boy Scouts, we used to collect and recycle newsprint to support the local BSA troop.  Was in this little town on outskirts of Cincinnati. I was a "bundler" and used to tie bundles of paper and magazines.  An older widow lady in town passed away and the BSA was called by the family to collect a bunch of her old magazines--which turned out to be Life magazines from about 1936 to late 40's.  Bundles and bundles of them.  Nobody realized then how collectible they'd eventually become.  I was just smart enough to grab a couple as I helped bundle the rest.  One was from May 1937 and had a pictorial on the disappearance and efforts to find Amelia.

Too bad you and your buddies didn't have the foresight back then to grab them all and stash them away in a safe place.  They would now be worth a  small fortune.  Of course, the late 60s was when a lot of history was being massively obliterated, and few people were interested in relics of the past.  Whole neighbourhoods were being "urban renewed" out of existence, and trashy crap built in their place. It was fashionable to discard stuff merely because it was "old", even though it was perfectly functional and of higher quality than anything new you could  replace it with.

That's also the era when "sideband for the masses" had hit the market, and a lot of solidly built homebrew ham rigs were trashed, with the owners replacing them with cheap, low quality, flimsy little transceivers like the early Swans, Galaxies and Heathkit "Hotwater" rigs.  Then the Japanese (Yaecomwood) came on the scene, and the rest is recent history.

I remember one old timer who was still on AM, but had been a wannabe slopbucketeer for years before he was finally able to afford a rig.  About 5 years after he had "gone SSB", I ran into him on the air, and he asked me if I had any plate transformers and power supply  components I would part with.  He wanted to build a leen-yar to go with his transceiver.  When I asked him why he didn't re-use the parts from his old 100THs modulated by 805s AM rig, he told me that after he got on slopbucket, he had hauled that rig out of the house and dumped the whole thing in a  sinkhole on the back of his property.  I chuckled and told him he wasn't getting any of my spare parts and that he had better look elsewhere.

[WU2D]

This plane has several antennas including an RDF Loop on top.

250 ft trailing long wire antenna was removed by Earhart and Noonan prior to their disappearance. (Source: Wikipedia.org) Presumably this was the main 500 kHz antenna.

The radio antenna of NR16020 ran from a mast on the cabin roof to both tailplanes. Presumably this was the main shortwave transmitting antenna.

There was also a belly aerial which I believe was used for receive only.

[k4kyv]

New information gives a clearer picture of what happened 75 years ago to Amelia Earhart and navigator Fred Noonan, where they came down and how they likely survived – for a while, at least – as castaways on a remote island.

http://www.csmonitor.com/USA/2012/0602/Amelia-Earhart-New-evidence-tells-of-her-last-days-on-a-Pacific-atoll-video

[WU2D]

I did some simple geometry and came up with some dimensions on the V antenna on the top of the plane. You can plainly see that there were insulators at the tails. The length of each antenna section appears to be 30 feet. Together these would be loaded somewhat by the body of the airplane so if I had to guess they would give a natural resonance of around 6-7 MHz with good radiation efficiency. So her 6110 kHz frequency would be served well. At her lower 3105 kHz frequency, the antennas would require some loading inductance, but they would still be quite efficient compared to an 8 ft mobile whip!

[W8VG]

This is really interesting stuff.  In the late 1960's when I was in Boy Scouts, we used to collect and recycle newsprint to support the local BSA troop.  Was in this little town on outskirts of Cincinnati. I was a "bundler" and used to tie bundles of paper and magazines.  An older widow lady in town passed away and the BSA was called by the family to collect a bunch of her old magazines--which turned out to be Life magazines from about 1936 to late 40's.  Bundles and bundles of them.  Nobody realized then how collectible they'd eventually become.  I was just smart enough to grab a couple as I helped bundle the rest.  One was from May 1937 and had a pictorial on the disappearance and efforts to find Amelia.

Too bad you and your buddies didn't have the foresight back then to grab them all and stash them away in a safe place.  They would now be worth a  small fortune.  Of course, the late 60s was when a lot of history was being massively obliterated, and few people were interested in relics of the past.  Whole neighbourhoods were being "urban renewed" out of existence, and trashy crap built in their place. It was fashionable to discard stuff merely because it was "old", even though it was perfectly functional and of higher quality than anything new you could  replace it with.

That's also the era when "sideband for the masses" had hit the market, and a lot of solidly built homebrew ham rigs were trashed, with the owners replacing them with cheap, low quality, flimsy little transceivers like the early Swans, Galaxies and Heathkit "Hotwater" rigs.  Then the Japanese (Yaecomwood) came on the scene, and the rest is recent history.

I remember one old timer who was still on AM, but had been a wannabe slopbucketeer for years before he was finally able to afford a rig.  About 5 years after he had "gone SSB", I ran into him on the air, and he asked me if I had any plate transformers and power supply  components I would part with.  He wanted to build a leen-yar to go with his transceiver.  When I asked him why he didn't re-use the parts from his old 100THs modulated by 805s AM rig, he told me that after he got on slopbucket, he had hauled that rig out of the house and dumped the whole thing in a  sinkhole on the back of his property.  I chuckled and told him he wasn't getting any of my spare parts and that he had better look elsewhere.

Hey Don,

I wish I'd at least grabbed a couple of big bundles after we were through.  A few of the kids grabbed up ones that had recognizable pictures of GI's and WW2 stuff, Hitler or Nazi's, DiMaggio, anything else they could recognize from history or sports.    The issues from war years were plentiful--and am afraid they were all recycled to make 1970's era store flyers.   

Was a travesty none of us recognized their value.  Being typical teens, we were constantly on lookout for old Playboys and the like but remember stashing a bunch of old PoPComm from late 50's and early 60's....and do remember salvaging old Heathkit catalogs from the piles. 

On the old gear, I remember seeing just a few folks trying to find new homes for it--almost always to avail.  As a kid, used to hit Cincinnati Stagfest (we've spent some time reminiscing on that one) and Dayton during that period--would see vintage rigs sitting there in flea market with $10 and $15 dollar price tags on them--all to be reduced to zero or put in dumpster by end of day.  Nobody wanted them--or wanted to take em home.   

My uncle was only exception I could remember.  After briefly trying SSB in late 50's he decided it wasn't for him.  Didn't like the tinny voice quality.   Unfortunately by 1970, he was reduced to transmitting AM and having everyone come back to him in SSB (used a 75A4 at time) as everyone in his daily round-table had given in.  He still refused.  When they'd kid him or worse, some slopbuckets down band would complain about him being "too wide" he'd crank it up another notch and growl back: "SSB is a just a fad, it's not here to stay!" <hihi>.   He became an SK in 1987 but suspect he'd still be running AM today and would enjoy all the current activity if he were around. 

73's
Geo W8VG/6

[N0WEK]

Back during the 1980s, when I was delivering small aircraft overseas, I first used a manual trailing wire antenna. I didn't use a tuner, I just ran out about the right amount of wire and fine tuned the length to minimize SWR using a cheap Rat Shack meter. That worked fine.

Later I used an Icom 725 with the AH-2 automatic tuner. I ran a wire from the hole where the ELT antenna usually sat, on up to the tail and out to the left wing; usually about  40-50 ft of wire. That would cover all the ARINC frequencies. A couple of times ice took the wing to tail part of the wire and only the upper freqs would tune on the 10 ft of wire left.

I once talked to a guy in California from Australia using only about 10 watts of power. I used to call Portishead radio in England from Africa for a phone patch back to the states. Height matters!

[Todd, KA1KAQ]

No need to do any calculating, simply pick up this handy item and conduct your own experiments:

http://tinyurl.com/bnxmcqg

Remove all speculation and find out the truth for yourself.

[n1ps]

nice find Todd.  Curious why the seller is offering shipping...its supposed to fly?

Nice thread.  TNX to those who posted the articles.

p

[K5WLF]

No need to do any calculating, simply pick up this handy item and conduct your own experiments:

http://tinyurl.com/bnxmcqg

Remove all speculation and find out the truth for yourself.

That has to be Linda Finch's bird from her Amelia Earhart re-creation flight. I saw that plane in '96 or early '97 when it was being restored and fitted out for her around the world flight at Ezell Aviation in Breckenridge, TX. Ezell does some of the best work I've ever seen. At the same time, there was an F4U Corsair and a B-25 (my favorite plane of all time) in the shop. The Mitchell looked better than it probably had on the assembly floor in Inglewood CA when it was being built. I hope the Electra goes to someone who'll appreciate and treasure it. The day I visited Ezell, there was also Howard Purdue's Junkers JU-52/3m German tri-motor sitting outside on the ramp awaiting restoration. Howard passed on recently and I heard he'd sold the Junkers a while back. Don't know for sure.