Topband: More on Power Coupling

[Robert Brown]

Friends in Radio Land -
 
In connection with magneto-ionic power coupling for the K1B
operation, it should be noted that similar effects would be
expected for other locations near the geomagnetic dip equator.
 
Some years ago, I pointed that out to Garry, NI6T, when he was
planning a DXpedition to the Pacific Ocean Area.  He knew of
facilities (aging towers) on Central Kiribati (T31) and it was
hoped that he might be able to explore the use of vertical AND
high horizontal antennas for N-S and E-W propagation studies on
160 meters from that location.  That trip did not prove possible
and, instead, he later participated in the K5K DXpedition to 
Kingman Reef.
 
Power coupling is similar at K5K (see the Nov 2000 issue of the
Low Band Monitor) and Garry kindly sent me the logs to be examined
in detail for any difference in contacts in the N-S and E-W
directions that would have resulted; but none was found, largely
due to poor statistics.  That DXpedition involved a single
antenna; it is still hoped that the next operation at T31 will
be able to explore the use of both vertical and high horizontal
antennas and have active participation of operators in South
America.
 
A summary comparison of power coupling for vertical antennas at T31 and
K1B is given below:
         
        		   T31		K1B
        		 (loss)       (loss)


         	North	 -2.9 dB      -2.8 dB    
                 E-W    -12.0 dB     -14.6 dB
                South    -2.6 dB      -2.8 dB 
               

73,
 
Bob, NM7M