Re: Electrically length


"thejim" <papageorgiou40@xxxxxxxxxxx> wrote in message
news:1148797792.419314.169880@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
What do we mean by saying "electrical length" of an antenna?


In free space a very thin 1/2 wavelength antenna will have a lenght equal to
492 devided by the frequency in MHz. In practical applications this length
will be somewhat shorter depending on several factors such as the diameter
of the conductor,if it is insulated, and what it is near. For frequencies
up to about 30 MHz the electrical length will be around 468 devided by the
frequency in MHz.

The same applies to the feedline. If you see something like velocity factor
of .66 or .8. This is the number you multiply the 492 by to get the
electrical length of 1/2 wavelength of the feed line.


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