To: Top Band and Contest reflectors
More on the JPS ANC-4. I really put it to good use during the CQ 160
phone contest, and would like to share how I did it.
I have two beverage feedlines coming to the operating position, and
three other receive antennas. One beverage feedline brings in the
"east" and "northeast" beverages, switched with a remote relay. The
other beverage feedline is the "JA" beverage. I built a switch box
which has five inputs and two outputs. There are two five-position
switches. With these two switches I can put any one of the receive
antennas on either receiver of the FT-1000D, or one antenna on both
receivers.
I have found that I rarely use the second receiver on a different
antenna from the main antenna. Thus, the second receiver is usually
switched (internally in the FT-1000D) in parallel with the main
receiver's antenna. The selector switch output that goes to the
second receiver input is also connected, through a 50 ohm switcable
attenuator, to the noise antenna input of the ANC-4. The second
switch is now used to select the noise antenna fed to the ANC-4. The
attenuator I use has 10db steps, and I have found 20db to be an
appropriate setting for most applications, but it is something you
have to experiment with.
I found that my "JA" beverage, essentially useless in the CQWW 160
phone contest, heard all the noise heard by my other antennas but
never heard the (weaker) signals from the east. It was perfect as a
noise pickup antenna!
If you have several beverages with individual feedlines coming to
your receiver, here's a useful thing to do with the beverage that
doesn't hear the signal! Use it as a noise antenna that doesn't
hear the signal you want to hear, but does hear the noise. This
even works on atmospheric noise, not just local power-line stuff!
The ANC-4 will cancel anything heard on both antennas but won't
affect what is heard only on the "receive" antenna. Your beverage
pointing in the "wrong" direction could be the "right" one to pick
up the stuff you don't want to hear.
This setup made many contacts possible that would not have been
made. It is not a perfect solution, just another trick in the
arsenal. Unfortunately it didn't help me to hear KL7Y, but at least
now I can hear people who have trouble hearing me!
73, Jay
w6go@netcom.com
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