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Old November 2nd 08, 12:37 AM posted to rec.radio.shortwave
Dave[_18_] Dave[_18_] is offline
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First recorded activity by RadioBanter: Jun 2008
Posts: 1,183
Default KFI transmitter off the air

Telamon wrote:
In article ,
"David Eduardo" wrote:

"Telamon" wrote in message
...
. :-)
You are such a retard. I was wondering what the line loss would be and I
am not familiar with the FCC rules. The 50Kw could be the max the
transmitter puts out or the input to the antenna or it could be based on
antenna field strength measurements.

There are several isssues here.

1. It's usually the licensed power into the antenna for non-directional
stations. So most new solid state transmitters deliver 10% to 20% more, so
that if the line loss is a couple of percent, the line is fed with the
licensed power plus line loss.

2. Directional systems feed the licensed power plus phasor loss to the
common point (input) of the directional phasor. So if phasor loss for a 50
kw station is 5 kw, then they feed the common point with 55 kw.

3. Some classes of AM service have a maximum field strength at a determined
distance. If the radiator is too efficient (a 5/8 wave or a Franklin) the
station may actually feed less than licensed power to the tower to
compensate for the radiation efficiency.


SNIP

The 5/8 wavelength antenna is a good one to use for local mobile
communications. I think that is because it has a good low to the horizon
lobe creating a better ground wave than a 1/4 wavelength antenna would
generate. That sound right to you or is there another reason?


That is correct. Most flamethrowers are electrically near 1/2 5/8
wave. Half wave antennas are harder to feed.