At WW2Y/K2TOP, we use T/R relays to electrically open all 4 elements of
the inverted L array during receive, since most Beverages run through or
near the transmit array. The normally closed contacts of a T/R relay are
placed across to short circuit the feed line 3/4 wavelengths from the feed
point of each inverted L, which translates to an open circuit at the feed
point. This technique makes the transmit array electrically invisible to all
receive antennas in the same environment. This method has been in operation
since the '96/'97 winter season without any problems.
Peter
|