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).
Tomas Hood, NW7US/HCDX)
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).
Tomas Hood, NW7US/HCDX)
