Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6 from
my radio across the attic and outdoors to a tree. I had maybe 10 extra feet
of coax so I wrapped it around the tree. I strung about 50' of #9 steel wire
between 2 trees going east/west about 15' above ground and attached the
copper conductor to it. I terminated the coax shield at the tree with a
ground rod. At the radio I attached the shield to the ground terminal and
the center cu conductor to the other am external antenna terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?

On Feb 21, 4:04*pm, "Jeff D" wrote:
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6 from
my radio across the attic and outdoors to a tree. I had maybe 10 extra feet
of coax so I wrapped it around the tree. I strung about 50' of #9 steel wire
between 2 trees going east/west about 15' above ground and attached the
copper conductor to it. I terminated the coax shield at the tree with a
ground rod. At the radio I attached the shield to the ground terminal *and
the center cu conductor to the other am external antenna terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?


When I was a kid I tried to pick up a 50Kwatt station that was about
100 miles away. I lliked the station because it always played the
music I liked while none of the local stations did. If I was 30 miles
south or east of my location I could pick it up fine on the car radio.
No antenna I tried worked reliably from my home. It was just too far
away.

Jimmie

Jimmie

Dear Jeff D (no call sign):

WSCR 670 kHz appears to be sports station - as you suggested. It streams
audio on the internet at:
http://radiotime.com/station/s_22732/670_The_Score.aspx

It is a 50 kW station with a nondirectional antenna. I had thought that it
might have a dip in your direction, which would explain why is was
especially weak.

In the AM broadcast band it is expected that the SNR (signal to noise ratio)
is externally determined when using some sort of antenna, which includes
what you described. In other words, you have not done anything wrong - the
probability is that the signal is too weak. Of course, if you have the room
for one or two km of beverage antenna pointing at Chicago, the results might
change, but I doubt it.

73, Mac N8TT

--
J. McLaughlin; Michigan, USA
Home:
"Jeff D" wrote in message
...
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6 from
my radio across the attic and outdoors to a tree. I had maybe 10 extra
feet of coax so I wrapped it around the tree. I strung about 50' of #9
steel wire between 2 trees going east/west about 15' above ground and
attached the copper conductor to it. I terminated the coax shield at the
tree with a ground rod. At the radio I attached the shield to the ground
terminal and the center cu conductor to the other am external antenna
terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?

Jeff,
How about finding a circuit for a pre amplifier for the MW band and building
it, I am sure that will make a difference, but if there is a strong or a
local station, it may swamp the receiver, but then you could construct a
trap.

Over here one can receive AM stations at that distance during the day, but I
guess it depends on how my RF crud there is in your area..

Two questions, what is the power of the station you are trying to receive?
What type of a receiver are you using?

Another thought is to decrease your coax length and increase the amount of
bare wire, more wire in the air the better.


John


"Jeff D" wrote in message
...
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6 from
my radio across the attic and outdoors to a tree. I had maybe 10 extra
feet of coax so I wrapped it around the tree. I strung about 50' of #9
steel wire between 2 trees going east/west about 15' above ground and
attached the copper conductor to it. I terminated the coax shield at the
tree with a ground rod. At the radio I attached the shield to the ground
terminal and the center cu conductor to the other am external antenna
terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?

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?
________________

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

On Feb 22, 5:51*am, Richard Fry wrote:

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).

To correct myself, loopsticks respond to the magnetic field of an EM
wave -- which, for vertical polarization, lie in the horizontal plane.

On 2/22/2010 8:54 AM, Richard Fry wrote:
On Feb 22, 5:51 am, Richard Fry wrote:

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).

To correct myself, loopsticks respond to the magnetic field of an EM
wave -- which, for vertical polarization, lie in the horizontal plane.

Hello, and this is a common misunderstanding, which may owe to the fact
of the response of a receiving antenna in a near (induction) field of a
transmitting antenna. In the far field (several wavelengths or greater)
from the transmitting antenna the receiving antenna responds to the
propagated electromagnetic field. Now, how a particular antenna is
oriented wrt this EM field will determine its ability to extract a given
amount of available power from the incident EM wave. One can of course
think of the action of loops or dipoles in the far field as per
Richard's statement but that sidesteps the underlying physics. Sincerely,


--
John Wood (Code 5520) e-mail:

Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

In article 1ehgn.267718$o06.4061@en-nntp-
08.dc1.easynews.com, says...
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6 from
my radio across the attic and outdoors to a tree. I had maybe 10 extra feet
of coax so I wrapped it around the tree. I strung about 50' of #9 steel wire
between 2 trees going east/west about 15' above ground and attached the
copper conductor to it. I terminated the coax shield at the tree with a
ground rod. At the radio I attached the shield to the ground terminal and
the center cu conductor to the other am external antenna terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?


Try disconnecting the ground rod at the tree and connect
the braid of the coax to the antenna input. Ground the
radio.

--- news://freenews.netfront.net/ - complaints: ---

"Jitt" wrote in message
m...
In article 1ehgn.267718$o06.4061@en-nntp-
08.dc1.easynews.com, says...
Trying to improve my reception from Chicago with baseball season
approaching. I'm about 100 miles sse in Indiana. I ran about 75' RG-6
from
my radio across the attic and outdoors to a tree. I had maybe 10 extra
feet
of coax so I wrapped it around the tree. I strung about 50' of #9 steel
wire
between 2 trees going east/west about 15' above ground and attached the
copper conductor to it. I terminated the coax shield at the tree with a
ground rod. At the radio I attached the shield to the ground terminal
and
the center cu conductor to the other am external antenna terminal.
It greatly improved my reception I get all the major Chicago sports
channels, but the one I was most interested in 670 is the worst. What all
did I do wrong and what can I do to improve 670?


Try disconnecting the ground rod at the tree and connect
the braid of the coax to the antenna input. Ground the
radio.

--- news://freenews.netfront.net/ - complaints: ---

Thanks for all the replies and help. I did try grounding at the radio but I
disconnected the shield at the radio not out at the outdoor connection. I'll
try Jitt's suggestion. I've goggled around on constructing a loop antenna
and it looks do-able for me so I may try that.
Most of the information I used to construct the long wire came from this
link http://www.hard-core-dx.com/nordicdx...b/coupler.html the
author also describes a coupler which I may attempt if I can scrounge the
parts unless anyone knows if something like that is available commercially.
Also could somebody recommend a lighting arrestor that would work with the
RG-6 male and female connectors where the long wire connects to the coax.

Jeff D wrote:

Thanks for all the replies and help. I did try grounding at the radio
but I disconnected the shield at the radio not out at the outdoor
connection. I'll try Jitt's suggestion. I've goggled around on
constructing a loop antenna and it looks do-able for me so I may try that.
Most of the information I used to construct the long wire came from this
link http://www.hard-core-dx.com/nordicdx...b/coupler.html the
author also describes a coupler which I may attempt if I can scrounge
the parts unless anyone knows if something like that is available
commercially. Also could somebody recommend a lighting arrestor that
would work with the RG-6 male and female connectors where the long wire
connects to the coax.

Fiddling with the long wire, couplers, and tuners will change both the
signal and noise by the same amount, which won't help you at all. You
might as well turn your volume control up and down. A loop, however,
gives you the ability to improve the signal to noise ratio by decreasing
the noise from some directions, so you can hear the station better.

Roy Lewallen, W7EL