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Here in new-zealand a number of lf hams used or
have used a phased wire or rod to alter the reception patterns to reduce
man made and natural atmosphere noise ..on lf...they could north only
sensitivity or throw a switch and listen south only..not used of course on
transmitting..havnt used that system my self as i am in a quiet country style
setting on southern edge of timaru.....but in early days 14years ago i was
blocked by s9plus 40 powerline carriers on lf band..they were generated on
north side of timaru city...i built a 16ft square loop tuned to lf..the sharp
null of the loop was aimed at the direction of the ham signal i wanted.
the big vertical was used as main general recieve antennae..the noise picked up
by the loop was fed out of phase with the vetical in a mixing amp..because the
loop had its null on the ham signal it couldnt be phased out...was published in
our breakin mag..i got so good the s9+ power carriers were just a faint
dribble . after a while they shut the power line system down..i
believe they now use OLD DOCTOR FINDLAYS modern methods hihi
george that all do now ..a bed time story for lfers bye
for now
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