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Author Topic: Ok, silly question time...  (Read 443 times)

KD7HNN

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Ok, silly question time...
« on: December 02, 2019, 11:28:16 AM »

With the 10m contest coming up, I'm doing some reading on Sporatic E propagation. I don't fully understand it yet, but my question is: Is there a particular direction I should point my beam for Sporatic E skip? I recall hearing something about South East but I don't remember where I heard it. The station I will be at is in CA.
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AF5CC

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Re: Ok, silly question time...
« Reply #1 on: December 02, 2019, 01:17:55 PM »

Sporatic E propagation can occur in about any direction.  You just have to listen and watch to cluster to see where the E clouds might be.

73 John W5TD
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K0UA

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Re: Ok, silly question time...
« Reply #2 on: December 02, 2019, 04:35:20 PM »

With the 10m contest coming up, I'm doing some reading on Sporatic E propagation. I don't fully understand it yet, but my question is: Is there a particular direction I should point my beam for Sporatic E skip? I recall hearing something about South East but I don't remember where I heard it. The station I will be at is in CA.

Yeah, well that is funny right there, I don't care who you are. :)  show me someone that fully understands it.

Point your beam where it works the best.
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73  James K0UA

KC6RWI

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Re: Ok, silly question time...
« Reply #3 on: December 02, 2019, 04:42:55 PM »

I don't think I've ever seen an e cloud.
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W1VT

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Re: Ok, silly question time...
« Reply #4 on: December 02, 2019, 04:51:30 PM »

https://www.dxmaps.com/spots/mapg.php

This site maps E skip paths and tries to calculate the cloud locations.
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K0UA

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Re: Ok, silly question time...
« Reply #5 on: December 03, 2019, 03:41:14 PM »

https://www.dxmaps.com/spots/mapg.php

This site maps E skip paths and tries to calculate the cloud locations.

It can be helpful.  I consulted it pretty close when I was going for WAS on 6 meters.   

Hasn't helped much with Hawaii and Alaska from Missouri though.  :)   Got the rest of them.
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73  James K0UA

KD7HNN

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Re: Ok, silly question time...
« Reply #6 on: December 10, 2019, 01:45:08 PM »

Ok, I think I understand the sporatic E skip thing now. It isn't something you can really predict, and yes I've never seen an Es cloud either. Ham Maps does give you a reasonable indication of Es, and the more experienced operators  have been known to track an Es cloud once it produces.

So help me understand back scatter and side scatter. What indications, if any, are there that this type of propagation is happening? I assume it's not direct bearing skip meaning I wouldn't point my beam to GA to talk to someone in GA, but maybe south east or North East. I vaguely remember a guy in CA talking about it. I *think* he said that he worked a bunch of east coast stations back scatter pointing his beam towards south america but dont recall his exact words. How does this work and at what azimuth?
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WB6BYU

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Re: Ok, silly question time...
« Reply #7 on: December 13, 2019, 10:56:27 AM »

Quote from: KD7HNN

So help me understand back scatter and side scatter...
How does this work and at what azimuth?



The pragmatic answer is, when you hear a station you want to work swing the beam to
peak the signal, whatever direction that happens to be.

The direction varies, depending on what paths are open at the moment and the relative
reflectivity of the surface of the Earth in that direction.

High power helps, too, as the reflection is usually rather lossy.

Imagine you have waves in the ocean with angled faces:  a signal of the right frequency
arriving at the ideal angle would reflect off the face of the wave back the way it came
if it is at right angles to the wave (or at a different angle otherwise).   Ideally the angles,
frequency, and wave height and spacing would all combine so that the reflections from
multiple waves are in phase over a reasonably large area.

If you are trying to work a station relatively close to you and the reflection zone is a thousand
miles out to sea,  you may need to point the beam nearly 90 degrees to the desired path.
But there are other sorts of reflectors as well, and in some cases you might have to point
South to work North if there is a good reflector in that direction.

Expect signals to be weak.

W1VT

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Re: Ok, silly question time...
« Reply #8 on: December 13, 2019, 11:05:19 AM »

Meteor showers are relatively predictable.

https://www.skyandtelescope.com/observing/interactive-sky-chart/
You may want to use this to see when meteors associated with the Geminids constellation are likely to appear.

Zak W1VT
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