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Brian
Moderators: Guru's, The Ministry
During a heavy rainstorm you are trying to receive fairly weak satellite signals through a very dense cloud which acts like a filter and prevents your receiver/dish from getting the maximum signal available. In addition the water droplets defract/deflect the signal meaning even less of the signal gets to your dish hence the loss of reception.511Flyer wrote:When the sky is overcast, like a heavy rainstorm, my SKY TV signal breaks up. So how does that relate to this theory?
This is different to the scenario above as we are talking about two ground based stations (one transmitting, the other receiving) rather than a ground based and space based system. With two ground stations signals can be 'bounced' off water laden clouds (depending on the frequency of the signal) which in turn makes them receivable over greater distances. Normally VHF and UHF radio signals are 'line of sight' and disappear off into space rather than following the curvature of the earth.FlyTexas wrote:When I was young I had a transistor radio which, on overcast evenings, could pick up very distant stations that I normally couldn't receive. This video made me wonder if this was possible because of the water content of the clouds.
Shortwave (or HF) radio is a very different beast in that it does follow the curvature of the earth and it is highly dependant on solar activity and the ionization of various layers above the Earth's surface. During the day HF is very short range as the solar interference kills the HF signals but as you get into twilight and then night proper so the range increases as you can bounce signals off the ionized layers where the sun is actually still shining. HF radio is also greatly affected by the 11-year 'sun-spot cycle' with the greatest communication distances coming at the times of sun-spot maxima.Garry Russell wrote:Radio is always better in the evening and night
Shortwave can be from the other side of the globe on some nights, then, next day it's just a few hundred miles.
- .... .- -. -.- ... / ...- . .-. -.-- / -- ..- -.-. .... / ..-. --- .-. / - .... . / .. -. ..-. --- / .-.. .- .-. .-. -.-- .-.-.-Tako_Kichi wrote:Let me see if I can shed some light on a few points raised based on my knowledge as a Ham Radio operator of many years standing.
..- .-. / ...- .-. -.-- / .-- . .-.. -.-. --- -- . / -.. . / ...- . ...-- -.-- . - / . -..- / --. .---- -.-- . -FlyTexas wrote:- .... .- -. -.- ... / ...- . .-. -.-- / -- ..- -.-. .... / ..-. --- .-. / - .... . / .. -. ..-. --- / .-.. .- .-. .-. -.-- .-.-.-![]()
Tako_Kichi wrote:..- .-. / ...- .-. -.-- / .-- . .-.. -.-. --- -- . / -.. . / ...- . ...-- -.-- . - / . -..- / --. .---- -.-- . -FlyTexas wrote:- .... .- -. -.- ... / ...- . .-. -.-- / -- ..- -.-. .... / ..-. --- .-. / - .... . / .. -. ..-. --- / .-.. .- .-. .-. -.-- .-.-.-![]()
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