John, N9JG wrote:
I am using an Orion to drive my Drake L-4B, and I operate mostly on 40
meters. My antenna is a 110 feet long dipole, center-fed with open-wire feed
line, and elevated about 30 feet with the support for one end attached to
the house chimney. My shack is in a 2nd floor bedroom, and the circuit
breaker panel is located in the basement at the opposite end of the house.
The house has a brick exterior, and one end of the antenna is only a few
feet from the shack.

When I operate high power on 40 meters, a GFCI equipped circuit breaker,
which is located in the house circuit breaker panel, moves to the open
position. None of my station equipment is attached to this breaker; this
particular breaker powers four outlets in the garage and two outlets on the
house exterior. None of these outlets are normally in use. Is it possible
(or even desirable) to install one or more bypass capacitors inside the
breaker panel, and immediately adjacent to, the ground-fault circuit
interrupter? If so, what type of capacitor is recommended?

John, N9JG



Hi John,

The quick answer is that anything that
will reduce common-mode currents on the
branch wiring will be a move in the
right direction. At 60 Hz, the GFCI is
supposed to trip at 5 mA. At 7 MHz, who
knows?

Some experimentation may be in order:
why not try ferrite beads on the wires
near the GFCI. Remember that common-mode
currents may enter the GFCI from either
direction. High-quality capacitors rated
for the voltages involved would work too
but seem like a less elegant solution.

If you do go with the caps, you can do a
test by plugging them into the outlets
not normally in use: a quick and dirty
approach that makes no permanent change
to the wiring. Be safe, of course.

Here's a link that talks a little about
this:

http://www.ce-mag.com/archive/06/ARG/webb.htm
Common-Mode Signals and Radiated Emissions

73,

Chuck

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Thanks for your comments and the link. A thought has just occurred to me
that perhaps I could damp out the rf energy in the unloaded wiring by
plugging a low wattage bulb (perhaps 5 watts) into one of the GFCI protected
sockets and see if that eliminates the problem.

Initially I had a small freezer in the garage plugged into one of the
sockets and some days later wondered why the freezer was no longer working.
At that time I discovered that the garage wall was also equipped with a
special non-GFCI protected socket which was installed by the house builder
specifically for a garage located freezer. After throwing out the spoiled
food and cleaning the freezer interior, I moved the freezer and plugged it
into the proper socket.

John, N9JG

"chuck" wrote in message
...
John, N9JG wrote:
I am using an Orion to drive my Drake L-4B, and I operate mostly on 40
meters. My antenna is a 110 feet long dipole, center-fed with open-wire
feed
line, and elevated about 30 feet with the support for one end attached to
the house chimney. My shack is in a 2nd floor bedroom, and the circuit
breaker panel is located in the basement at the opposite end of the
house.
The house has a brick exterior, and one end of the antenna is only a few
feet from the shack.

When I operate high power on 40 meters, a GFCI equipped circuit breaker,
which is located in the house circuit breaker panel, moves to the open
position. None of my station equipment is attached to this breaker; this
particular breaker powers four outlets in the garage and two outlets on
the
house exterior. None of these outlets are normally in use. Is it possible
(or even desirable) to install one or more bypass capacitors inside the
breaker panel, and immediately adjacent to, the ground-fault circuit
interrupter? If so, what type of capacitor is recommended?

John, N9JG



Hi John,

The quick answer is that anything that will reduce common-mode currents on
the branch wiring will be a move in the right direction. At 60 Hz, the
GFCI is supposed to trip at 5 mA. At 7 MHz, who knows?

Some experimentation may be in order: why not try ferrite beads on the
wires near the GFCI. Remember that common-mode currents may enter the GFCI
from either direction. High-quality capacitors rated for the voltages
involved would work too but seem like a less elegant solution.

If you do go with the caps, you can do a test by plugging them into the
outlets not normally in use: a quick and dirty approach that makes no
permanent change to the wiring. Be safe, of course.

Here's a link that talks a little about this:

http://www.ce-mag.com/archive/06/ARG/webb.htm
Common-Mode Signals and Radiated Emissions

73,

Chuck

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