On Dec 21, 3:26*am, wrote:
Dear All,

I have some beginners questions regarding antennas:

*** Why is it difficult to design and construct HF transmit antennas
for high power PEP, compared with low power 100 W?
Conceptually what is the difference between the two in design,
material construction?
Why do people find the high power harder to design and construct?

*** I understand that omnidirectional antennas transmit in all
directions with almost equal gain. Is it hard to design HF antenna
with directional gain in one direction and minimum in other
directions?
How is this done( conceptually): electrical length, material
contruction?

*** HF wire antennas: can these be for high power transmission and
directional gain ( guess the would always be omnidirectional)?

*** How is angle of transmission with the horizon (elevation)
controlled in a HF antenna ?

*** Can receive antennas also be diectional or are they always
omnidirectional receiving from all sides?
Do receive antennas have power ratings?

Thank you

Vijay


Vijay,

? Are you talking about High Power 1~2 KW Rated Antennas
vice Low Power 10~100 Watts Rated Antennas for use in
Amateur {Ham} Radio Broadcasting ?

* Check-Out the American Radio Relay League (ARRL)
ARRL - http://www.arrl.org/

* The ARRL Handbook for Radio Communications
http://www.arrl.org/catalog/?item=NO-HB2008

* The ARRL Antenna Book
http://www.arrl.org/catalog/?item=9876

* The ARRL Antenna Compendium Volume 7
http://www.arrl.org/catalog/?item=8608

* Thje ARRL Practical Wire Antennas # 2
http://www.arrl.org/catalog/?item=9563


? Or are you talking about High Power 50/100/250/500 KW
Antennas for Shortwave Broadcast Radio use ?

* HRS Type Antennas are more or less the Standard Antenna
used for Long Distance High Power Shortwave Broadcasting.
http://en.wikipedia.org/wiki/HRS_type_antennas
Th HRS Antenna is Curtain Antenna composed of a Dipole
Array; consisting of Rows and Columns of Dipoles.
http://hireme.geek.nz/HRS_antennas.html

* * ALLISS is a fully rotatable Antenna System
for High Power Shortwave Radio Broadcasting.
http://en.wikipedia.org/wiki/ALLISS

* * Dipole Antenna {Hertzian}
http://en.wikipedia.org/wiki/Dipole_antenna

* * Log-Periodic (LP) Antenna Array
http://en.wikipedia.org/wiki/Log-periodic_antenna

* * Antenna (Radio)
http://en.wikipedia.org/wiki/Antenna_%28radio%29

* International Shortwave Radio (HF) Broadcasting
http://en.wikipedia.org/wiki/International_broadcasting

* Shortwave Radio operates between the High Frequencies
(HF) of 3 MHz (3,000 kHz) and 30 MHz (30,000 kHz)
http://en.wikipedia.org/wiki/Shortwave
http://en.wikipedia.org/wiki/High_frequency


iane ~ RHF