[HCDX] Is HF propagation reciprocal? (and, De-mystifying HF propagation)

["NW7US, Tomas" <nw7us@xxxxxxxxxxx>]

Hello, fellow SWL'er and potential Amateur Radio Operator:

I'm letting this list know about some additions to my website  
( http://hfradio.org/ ).   These new pages contain information that many  
radio operators will find useful (based on the feedback I have gotten from  
this material when the original was published in CQ Magazine and Popular  
Communications Magazine).

One would think that ionospheric radio propagation would be reciprocal.  
That is, the signal strength in one direction should be the same as in the  
reverse, or reciprocal, direction. In HF ray-trace theory, the distance is  
the same and the ionospheric control points-the points where the wave is  
reflected (or more properly, refracted) back to the ground-should be the  
same.  This is an interesting topic for those using very low power, for  
example.  Can your signal be heard well at the distant station, and can it  
compete with other signals that might be originated with a higher energy  
level?

I explored this (is HF propagation reciprocal?) in a recent CQ Magazine  
"Propagation" column.  I've posted the meat of the text at:

http://hfradio.org/ace-hf/ace-hf-reciprocal.html

I've also posted another recent CQ Magazine "Propagation" column, where I  
explored basic HF propagation concepts (De-mystifying HF signal  
propagation).  This is interesting from the "listener's" perspective.

You can find it here:

http://hfradio.org/ace-hf/ace-hf-demystified.html

I'm working on posting additional texts where I take various HF  
propagation topics, and use modern software to model the concepts.  I hope  
that this is helpful to those of you wishing to dig deeper into space  
weather and radio signal propagation (especially on HF).

73 es gud DX

Tomas Hood / NW7US / Heliophile
http://propagation.hfradio.org  -and- http://cw.hfradio.org/

: Propagation Editor for CQ, CQ VHF, Popular Communications :
: Associate Member of Propagation Studies Committee of RSGB :
: 122.93W 47.67N Brinnon, WA USA CN87 - QRP and CW/SSB/DIGI :
: 10x56526 : FISTS 7055, FISTS NW 57 : Lighthouse Scty #144 :
: NAm QRP CW Club 1774 : QRP Amateur Radio Club Int'l 12781 :
: Contributing editor on Wikipedia - Amateur Radio/Space WX :
: The journey of life http://ic-discipleship-ministries.org :

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