I picked up these numbers today while investigating info on tuning my father-in-laws cb antenna. The author probably has good basis for his report and provides an interesting comparison of antenna length to power. While we were at AES in Orlando a couple of months ago during our Club’s Ham-A-Rally I was shopping some antennas. The sales hams in the store told me the obvious, length makes a difference.
Here are some numbers from an article entitled, “<How does an antenna size affect my CB radio?” to paint the picture a little more precisely:
- If you put 4 watts into a four-foot antenna, you will get the same power out of that antenna as if you were putting 2 watts into a 102-inch whip.
- If you put 4 watts into a 3-foot antenna you will get the same power out as if you wre putting about 1.5 watts into a 102-inch whip.
- If you put 4 watts into a 7.5 inch antenna on a hand held CB, it would put out as much power as a third of a watt into a 102-whip.
- If you put 4 watts into a 102-inch whip antenna, it is the same output as if you put 11 watts into a 3-foot whip.
- If you put 4 watts into a 102-inch whip antenna,, it is the same as if you put 14 watts into a 28-inch antenna.
- If you put 4 watts into a 102-inch whip antenna, it is the same as if you put 54 watts into a 7.5 antenna.
N5RTG Jim
source: http://www.howstuffworks.com/framed.htm?parent=question490.htm&url=http://www.offroaders.com/info/tech-corner/reading/swr.htm and select antenna size under Related Information