WiNRADiO G33DDC User’s Manual
15
A "good" ground for a shortwave receiver is one that provides a low
impedance path to ground for radio signals in the frequency range of interest.
A metal cold water pipe located in close proximity to a possible ground
connection point could provide good results. If no such point exists, a copper
stake hammered into the ground may be required. Copper earth stakes can be
obtained from electrical supply outlets.
Assuming a typical installation where the coaxial cable to the receiver enters
the building at some point, an opportunity may exist to make a connection
between the outer shield of the coaxial cable and the suitable ground point. In
order for the grounding to be effective, the connection between the ground
point and the coaxial cable outer should preferably be no more than a few
meters in length. A low impedance connection (such as braid removed from a
section of coaxial cable) should be used to make the connection. In an ideal
situation, the length of coaxial cable to the receiver would be no more than a
few meters in order to provide a low RF ground impedance at the receiver.
In order to make a connection to the coaxial cable, a number of options exist.
These include WiNRADiO antenna accessories such as the
WR-CMC-30
Common Mode Choke
(see
www.winradio.com/cmc30
) or the
WR-LWA-0130
Long Wire Adapter
(sometimes referred to as a
“
long wire
balun
”; see
www.winradio.com/lwa
) which, along with their other intended
purpose, also provide a convenient ground connection stud that will allow the
connection to be made.
CAUTION: With any outdoor antennas, be sure to install a lightning
arrestor and disconnect the antenna (and ground it if possible) during
thunderstorms. To prevent receiver damage from static charge build-up,
always ground your antenna momentarily before connecting it to the
receiver.
If it is too difficult to make ground connections near the building, it may still be
well worthwhile experimenting at a point where connections can be more
made more easily. The
WR-CMC-30
Common Mode Choke
makes it
possible to provide several grounding points along the entire length of the
antenna feedline, in those locations where good quality grounding is available.
Where small physical size is important, magnetic field loop antennas usually
perform best. For indoor applications, WiNRADiO also offers the miniature
AX-17C antenna (see
www.winradio.com/ax17c
) which does not require
grounding.
