On Sun, 2 Apr 2006 22:54:10 -0400, "Yuri Blanarovich"
wrote:

They might say "60 degree top loaded resonant radiator" but they don't
say "60 degree tall radiator 90 degree resonant".

If you stick the coil at the base in series with radiator and bring it to
resonance (zero reactance at the frequency of interest) what "degree
resonant" will than radiator become, if not 90? ("Measured" from the feed
point, through the coil and then straight radiator.)

Hi Yuri,

This must be a convention that is particular to only a very few Hams.
The FCC database describes AM antennas in both electrical and physical
height as follows.

WGOP 80.00° tall 125.2 meters tall 540 kHz
WWCS 63.50° tall 98.8 meters tall 540 kHz
WFTD 79.00° tall 64.0 meters tall 1080 kHz
KYMN 118.60° tall 92.3 meters tall 1080 kHz
WWLV 90.00° tall 47.2 meters tall 1620 kHz
WTAW 204.00° tall 106.7 meters tall 1620 kHz

There may be some discrepancy, but it certainly looks like antenna
specification is by the electrical equivalent of the physical height
(and whatever l/d fudging) and with only one happening to be 90°.

Further, given most references (for professionals) is aimed at a
common specification that is largely driven by this agency, it would
seem odd to step out of this expectation to change to calling all
antennas 90° simply because they resonate.


http://www.fcc.gov/mb/audio/amq.html

73's
Richard Clark, KB7QHC