It dawned on me that the noise levels on my little 30 meter transceiver
were high, too high, and I began investigating and "Googling" various
fixes. I wasn't hearing atmospheric noise...and my old stand-by beacon
(W0ERE) hadn't been heard in some time. Removing the ground wire from
my computer actually caused the noise to decrease.
I have an end-fed, 135', inverted-L. The antenna comes under the window
sill and connects to my L-network coupler about 1.5' from the window.
The coupler has the inductor as the shunt element as I have a 22kW AM
BCB station 3km away and I need the high-pass response.
Ground wire (attached to the tuner and shack ground) exits the window,
goes down about 8 - 9' and attaches to a ground rod. Attached to the
rod is a fan of 3 or 4 radials, about 60' each, laid out on the ground
in the backyard.
W8JI's site was adamant that my problem was common-mode and the result
of bringing the antenna into the shack. One proposed fix, was to
install a 1/4 wire to the station/tuner ground. I can't recall where I
read this.
I installed a 1/4 wave wire right where the ground exits the window and
ran it out to a nearby tree...about 10' off the ground. The noise
totally disappeared.
I operate QRP, my 10 Watt K2 is my highest power rig. With my little
home-brew transceiver (<2 Watts), that same evening I worked UA6EX (5589
miles). This antenna has always been a great performer, working UA6EX
came as no great surprise.
QUESTION: The tuner settings didn't change much. I surmise that my
ground on 30 meters is now a low-Z...and the RF-in-the-shack problem
went away. Is that right? What happened here?
Jerry W
KI4IO
Warrenton, VA
I never understood the increased noise on 30 meters. I did change from
a Z-match coupler to this L-network awhile back. I wonder if that was
it?
And, with the success of getting rid of the noise on 30 meters, I
installed 1/4 wave wires for all bands attached to my ground, same as
the 30 meter wire
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