A question

Category: Broadcaster's Lounge

Post 1 by nikos (English words from a Greek thinking brain) on Wednesday, 01-Feb-2006 17:04:45

Hi all.
Can anyone tell me why on medium wave we get more stations during the night than during the day?
I was always wondering that and i would be grateful if somebody can explain to me.
Nikos

Post 2 by KC8PNL (The best criticism of the bad is the practice of the better.) on Wednesday, 01-Feb-2006 23:32:19

Geiasou Nikos.
I'll try and make this explanation as simple as possible. Basically, when a signal is transmited, it goes up in to the atmosphere. The signal is hampered by a layer of the atmosphere called the ionisphere. The ionisphere is, of course, generated based on ions given off by the sun. So, durring the day while the sun is on your side of the Earth, the ionisphere is thicker, thus observing signals faster and not allowing them to travel as far. When the night time comes and the sun goes down, the signals can then travel further, because the ionisphere is not in their way as much. U especially notice it on the medium and shortwave bands because of the way signals at these frequencies travel. Unlike signals transmited on the VHF bands and higher, these signals travel at an angle, thus making them easier for the ionisphere to monipulate. That's the simple explanation, though a complicated one would require a book to write. Hope this helps.

Post 3 by nikos (English words from a Greek thinking brain) on Thursday, 02-Feb-2006 4:29:57

Thanks a lot. Your explanation was really good.

Post 4 by KC8PNL (The best criticism of the bad is the practice of the better.) on Thursday, 02-Feb-2006 7:21:40

NNo problem. Radio is one area where I actually have some technical knowledge, so if u have other questions, feel free to ask.

Post 5 by laced-unlaced (Account disabled) on Thursday, 02-Feb-2006 14:49:27

yes. agree with what scott said