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USAF High Frequency Global Communications System

AHM

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So you have me intrigued. I got an upconvertor for my SDR but my discone antenna isn't rated to go that low. Is there an easy (or affordable) antenna design to tune into those frequencies?
Uh, maybe this?

I have no idea. It popped up when I went looking (unsuccessfully)
for the amplified loopstick my Elmer had in 1980.
 

AHM

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string a long piece of wire (10'-100') from the upconverter's center pin of the HF port you should hear something. <10Mhz at night time and >10Mhz during the day.
Of course, you're not wrong.
I ran my tube SW receivers in high school off an end-fed (end-feeding?) random length wire -
a few dozen feet long, maybe 8'-10' above the ground. Only concession to convention
was I routed it into my bedroom via a (1950's?) ceramic-cased TV lightning arrestor.

(Scrap magnet wire from junior high school metal shop. Every messed-up DC motor project
field coil or armature meant more antenna wire for me).
 

Baby Billy

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string a long piece of wire (10'-100') from the upconverter's center pin of the HF port you should hear something. <10Mhz at night time and >10Mhz during the day.
I'll ask the dumb question. Can I lay out across the ground? Stringing it through a tree or some other high structure would be something I'm not currently capable of.
 

Uzi2

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I'll ask the dumb question. Can I lay out across the ground? Stringing it through a tree or some other high structure would be something I'm not currently capable of.

Usually any antenna works better the higher it is from the ground ( with a couple of exceptions ). Just getting it up four or five feet on T posts with an electric fence insulator on each one will improve performance.

T posts can be had for cheap as can insulators. Hammer the posts in the ground, snap the insulators on and mount your wire on them. Directional orientation of the wire is not really critical, it will work.
 
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AHM

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I'll ask the dumb question. Can I lay out across the ground? Stringing it through a tree or some other high structure would be something I'm not currently capable of.
To compare and contrast with @Uzi2's constructive post above...

Schematically, this...
21c42fe8d2c6a9c9b663c53b7fa3dba6.png

...is like that longwire receiving antenna I had in high school.

Except that I didn't have a "SUPPORT (Pipe or Mast, etc)" -
I had a ginormous hook eye screwed into the outside window trim
that used to hold the pulley for the second clothes line,
dating back to when my mother had no electric dryer and a baby in diapers.
The "INSULATOR at each end" were 1cmx2cm scraps of ¼" plexiglas from metal shop,
with two teentsy holes drilled through the faces.
The "SUPPORT (Tree, pipe, pole, e" was the 20' iron pipe w/ two ginormous hook eyes
my father had sunk at the property line in 1953 to support (both) clothes lines.

The house pulley hooks were high enough that no one was clotheslined
by the clothes lines when they walked along the house. So neither did the antenna
decapitate anyone.


Ham operators, er, pine for trees to string their wire antennas.
But in some sense they don't exactly string 'em through the trees.

The ropework looks like this:
longwire.gif

But the pulley isn't attached to an eye hook screwed into a tree.
The pulley is tied to a piece of parachute cord that's flung over a branch.
You downhaul on the paracord until the pulley contraption is up in the air,
then tie the paracord around the tree trunk. Bonus points if you tie the
paracord to the tree high enough that a kid can't reach to untie it - but
that just takes adult stature and a stepstool - not renting a cherry picker.

All this is an installation good enough to be permanent - better than seasonal,
let alone a week or two of tuning around before you lose interest.
So you can cut all kinds of corners if you don't want to invest the time
just to check out the shortwave bands.

Let's assume you've got the rheumatiz or you fell off the ladder
the last time you tried to clean the gutters, and you're not looking
to build a model of the Brooklyn Bridge on your lawn.
If you once toss one fishing sinker with paracord over one adequate tree branch,
all the rest of the excitement takes place down on solid earth.
If you have a salt water rod longer than the height of the branch,
you can just droop a sinker over the branch without even casting.

Hope this helps.
 

Baby Billy

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It kinda helps, and sure was funny. I have enough trees but then I would have to have the down lead running across my yard somewhere. Somewhere I would have to mow and the dogs and people would travel.

I put up 2 posts for a dog run that are no longer used that are pretty far apart. Ideas.
 

AHM

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It kinda helps, and sure was funny. ...
Thankew. Over the decades it gradually occurred to me to wonder
why the house had two clothes lines, but by the time I'd reached the age of reason
my mother stopped using the one accessed from my room.

It's only in the past year or so that I've come to realize that
I was sitting on the reason why they once needed two clothes lines.

(I pre-date Pampers).

I have enough trees but then I would have to have the down lead running across my yard somewhere. ...
Just to belabor [horse] the point: my vision is the longwire is suspended between:
  • Whatever window is closest to your radio shack/computer room/man cave
    • -and-
  • Some distant tree (or even a tool shed; I'm agnostic).
But if that just doesn't fit your layout, that's fine.
 

Uzi2

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It kinda helps, and sure was funny. I have enough trees but then I would have to have the down lead running across my yard somewhere. Somewhere I would have to mow and the dogs and people would travel.

I put up 2 posts for a dog run that are no longer used that are pretty far apart. Ideas.

They'll work.
 

AHM

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They'll work.
I wasn't reading carefully.

Dog run posts should make epic shortwave towers -
if you look carefully that's what the BBC has atop Broadcasting House...
BBC Broadcasting House.jpg

...not the flagpole - the two trusswork towers like the antenna on this FCC seal....
fcc-seal-bw-2020-large.png
 

timbo

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So you have me intrigued. I got an upconvertor for my SDR but my discone antenna isn't rated to go that low. Is there an easy (or affordable) antenna design to tune into those frequencies?
If you're talking about the HF frequencies, just a random length of wire would probably suffice, say 25-30 feet and as high as you can get it. These are very strong stations transmitting these messages so when the propagation is favorable, you shouldn't have any problems hearing them.
 
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