long wire AM antenna
On Feb 21, 3:04*pm, "Jeff D" wrote:
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. snip What
all did I do wrong and what can I do to improve 670?
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WSCR is a "Class A" 50 kW, omnidirectional station with no other
stations close enough geographically to cause co-channel interference
to their daytime groundwave signal even 150 miles from their transmit
site (at 41 56 North, 88 04 West). They use a 182-degree vertical
radiator.
The FCC's groundwave propagation curves for WSCR show that about a 2
millivolt/meter field intensity should exist at your location maybe
110 miles away, over the 8 mS/m ground conductivity for that path.
Normally that field intensity should provide fairly noise-free
reception even on an inexpensive, indoor clock radio. Other things
equal, your daytime reception quality should be nearly identical for
WSCR and WGN (720 kHz).
You might try using a vertically-polarized receive antenna, as that is
the polarization being broadcast. It doesn't need to be high above
the earth - in fact the lower end of it can be nearly touching the
earth and connect to the center conductor of your coax, with the coax
shield going to a good r-f ground. The required protection from
nearby lightning strikes should be used with it if it installed
outside.
The loop antennas suggested by others may work well, as they are
vertically polarized for the E-field (as is the loopstick of a typical
consumer-type AM broadcast receiver).
One other possibility is that a local noise source produces more
interference for you on 670 kHz than on the other channels you're
trying to receive. That will take some investigation.
Good luck,
RF
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