Volume control vice day time/night time

Is there a reason why some stations will come in loud and clear at night vice day. I have notice at night I will pick stations as far away as Canada, and I live in Virginia. These stations will come in crystal clear, volume control works fine, I can raise and lower the pitch no problem. Come day time the same station come in, but the volume does not function as it does for the night. (Is not as loud as it was during the night) If I hold/touch the back of the antenna backboard it does make a difference in the volume of the station.

I am just curious as to why this phenomena occurs if that is what it is ? If not any suggestion as to what might be causing this????


Frank

The signal bounces off the ionosphere differently at night than in the day reaching out much further.

Also, If you listen in the early evening on your nearby stations you may hear a short silence with a sound like there is switching going on, with the station sounding slightly different afterwards. Many stations alter the characteristics of their antennae between day and evening broadcasting to accommodate the atmospheric differences and it's effect on their propagation.

Additionally many stations are required to limit their power at night or even go off air completely, while others can run ful power...

More than you ever wanted to know about classification of radio stations from clear channel(generally 50Kw) down to grave yard stations(locals limited to a Kw max)...

http://www.oldradio.com/archives/stations/ccs.htm

Another aspect is interference.

Most businesses and causes of RFI are closed and turned off and not "fighting" with weaker signals.

During major holidays I can hear weak, small town (low power, locally owned) AM radio stations come in crystal clear and loud vs. typical days of the week when they are a-wash in hash, static, fuzz and fade