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Author Topic: HF propagation on other planets?  (Read 81607 times)
AD7DB
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« Reply #15 on: August 14, 2014, 08:42:55 AM »

Why bother with HF?  Phobos and Deimos would make great relay satellites.
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K2GWK
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« Reply #16 on: August 16, 2014, 01:27:18 PM »

Very true. A planet needs a molten core to generate a strong field and Mar's core cooled long ago. As a result the most of atmosphere was stripped away over eons by solar radiation and with it ionosphere. 

Did you read the article in Post #4?

http://sci.esa.int/mars-express/51056-new-views-of-the-martian-ionosphere/

Quote
High above the main body of Mars' atmosphere is a region of weakly ionised gas, known as the ionosphere. For the last eight years this poorly understood region has been observed by instruments on board ESA's Mars Express orbiter, and new studies show that the dayside ionosphere is more variable and more complex than previously thought.


Scientists have detected an ionosphere on Mars although a rather thin one with only two layers or are you going to claim the scientists are wrong and you right?.
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AB9TA
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« Reply #17 on: August 16, 2014, 08:54:23 PM »

According to this article from Jet Propulsion Labs, http://descanso.jpl.nasa.gov/Propagation/mars/MarsPub_sec2.pdf , Mars does indeed have a usable ionosphere for over the horizon HF propagation. It is nominally 1/10 the density of the F2 layer on earth.. It is much less stable, and has much lower MUF values than we are used to on Earth. But according to the JPL scientists, it would be usable for communications.
Phobos and Demios are both close to the Martian surface and orbit very quickly. They would only be visible for a few hours at a time, not long enough for reliable communications. They are also small, around 11km in diameter, meaning that your antenna aiming problems are pretty hairy, you have to track a small, fast moving, and not very reflective rock to bounce your radio waves from. HF may be the only way initially to communicate over the horizon...
Google and Wikipedia are our friends!!!

73!
Bill AB9TA
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SWMAN
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« Reply #18 on: August 16, 2014, 09:04:58 PM »

Some people just don't have a sense of humor.( as dull as a butter knife )
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W8JX
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« Reply #19 on: August 18, 2014, 01:12:40 PM »

Scientists have detected an ionosphere on Mars although a rather thin one with only two layers or are you going to claim the scientists are wrong and you right?.

I do not disagree than a very thin and unstable ionosphere is present on Mars but the point I was making is that a few billion years ago Mars had a atmosphere and a magnetic field to protect it but when core cooled the magnetic shield was lost and atmosphere was stripped away by solar flares and radiation.  One of the major concerns for extended stays on Mars is lack of native protection from solar and cosmic radiation due to lack of magnetic field. Lack of thick atmosphere and very thin ionosphere makes satellite relay a breeze.
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All posted wireless using Win 8.1 RT, a Android tablet using 4G/LTE/WiFi or Sprint Note 3.
W3RSW
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Posts: 127




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« Reply #20 on: September 23, 2014, 04:14:03 PM »

Well you better have a super noise blanker for Jupiter qso's.  Peak Natural RF around 18 MHZ or so. Lightning spectaculars. Float your shack deep down in the atmosphere at say the one atmosphere zone and/or the 20 C temperate zone.

Enjoy sailing in winds of hundreds of miles per hour; string that zep out behind your blimp.
Breathe in those pungent early morning vapors, ammonia wafting through your nostrils. Guarenteed to spark your day if you get an arc from your key.  Although come to think of it Methane without oxygen won't be explosive.

Big planet, hops around the long path will be many times longer, much weaker and statically challenged.  Direct path hops will be too. No limit on power though for your rig. Your blimp can convert static electricity,  all you can gulp, into lower voltage, higher current power for your rig.  Just hang some wire down into the next zone or two for that differential tingle. 

Just think of the possibilities, Hydrogen, methane, ammonia for the asking.  -With all the power available easily converted into chemicals of choice in your handy dandy Acme Jigger, tm.

Just think of all the ionization layers though,   A through z, alpha through omega. Grin
Surely several of them will open horizons far greater than dreamed of in our little world.

Let's see, worked ZZOflipps today on H prime sporadic Q.

And moon bounce?  How about three, four or ten bounce? Extra points for verboten bounce off Europa...  An Interspacial no no for any kind of contact there, of course.  Boots and Pirates arrested daily ...  Hear they've discovered amplified signals , actually transposed from there although officialdom won't acknowledge or recognize such.

An on and on.  Just take your own oxygen if you can't afford a Unicode Element, tm. Transmutation reactor.  All better hams the system over go with complete kit though.



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K4VSR
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« Reply #21 on: September 28, 2014, 03:40:07 AM »

Great location for DXpedition, call me first. K4VSR, Jim
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