I'm inside an office inside an old brick and steel factory and can get very
little AM reception, only a few of the stations located in the same city. I
ran RG6-U coax to the roof of the factory (appx.100ft) and considered buying
a loop antenna but at this groups suggestion connected the coax to a long
wire. The stations I'm interested in are Indianapolis 1070kc and Chicago
670kc & 1000kc. I installed 200ft of #12ga insulated wire that is orientated
in line with these 2 cities and 6' above the roof at the terminations and
3-4' in the center. I grounded the coax shield at the roof and in my office
and I'm using a GE Superadio III on batteries. I can get these stations fine
in the daytime with a reasonable amount of static but at night the static
increases severely. Is there anything else I can do to make this a better
antenna.

Thanks in Advance
Jeff

On Tue, 29 Nov 2005 10:15:37 -0500, Jeff Dieterle wrote:
I'm inside an office inside an old brick and steel factory and can get very
little AM reception, only a few of the stations located in the same city. I
ran RG6-U coax to the roof of the factory (appx.100ft) and considered buying
a loop antenna but at this groups suggestion connected the coax to a long
wire. The stations I'm interested in are Indianapolis 1070kc and Chicago
670kc & 1000kc. I installed 200ft of #12ga insulated wire that is orientated
in line with these 2 cities and .....
^^^^^^^
???????

In-line? The wire should be broadside to the desired path of propagation.


... I can get these stations fine
in the daytime with a reasonable amount of static but at night the static
increases severely. Is there anything else I can do to make this a better
antenna.

You never mention how far away you are from "... Indianapolis 1070kc and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

Ya I know, if I move it to right angles the length will shorten to around
40ft. Do you think it would make much difference ?
"Allodoxaphobia" wrote in message
...
On Tue, 29 Nov 2005 10:15:37 -0500, Jeff Dieterle wrote:
I'm inside an office inside an old brick and steel factory and can get
very
little AM reception, only a few of the stations located in the same
city. I
ran RG6-U coax to the roof of the factory (appx.100ft) and considered
buying
a loop antenna but at this groups suggestion connected the coax to a long
wire. The stations I'm interested in are Indianapolis 1070kc and Chicago
670kc & 1000kc. I installed 200ft of #12ga insulated wire that is
orientated
in line with these 2 cities and .....
^^^^^^^
???????

In-line? The wire should be broadside to the desired path of propagation.


... I can get these stations fine
in the daytime with a reasonable amount of static but at night the static
increases severely. Is there anything else I can do to make this a
better
antenna.

You never mention how far away you are from "... Indianapolis 1070kc and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

"Jeff Dieterle" wrote in message
...
Ya I know, if I move it to right angles the length will shorten to around
40ft. Do you think it would make much difference ?
"Allodoxaphobia" wrote in message
...
On Tue, 29 Nov 2005 10:15:37 -0500, Jeff Dieterle wrote:
I'm inside an office inside an old brick and steel factory and can get
very
little AM reception, only a few of the stations located in the same
city. I
ran RG6-U coax to the roof of the factory (appx.100ft) and considered
buying
a loop antenna but at this groups suggestion connected the coax to a
long
wire. The stations I'm interested in are Indianapolis 1070kc and Chicago
670kc & 1000kc. I installed 200ft of #12ga insulated wire that is
orientated
in line with these 2 cities and .....
^^^^^^^
???????

In-line? The wire should be broadside to the desired path of
propagation.


... I can get these stations fine
in the daytime with a reasonable amount of static but at night the
static
increases severely. Is there anything else I can do to make this a
better
antenna.

You never mention how far away you are from "... Indianapolis 1070kc and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK


One wavelength at a frequency of say 1070 kcs is a little less than 300
metres (approx 1000 feet?).
An antenna of either length will be very 'short' compared to the
'wavelengths' involved and will not be close to resonance.
e.g. For quarter wave resonance (approx 75 metres or about 250 feet; for
1070 kcs and nearly 400 feet for say 670 kcs ) required.
Any 'too short' antenna will be will be badly mismatched (energy loss!) to
the impedance of the co-ax.
This suggest that some kind of untuned impedance matching transformer,
suitable for the frequencies in question, might be used to transfer as much
energy as possible to the co-ax transmission line?
Seen this done with short 'whip' antenna operating at Broadcast Band/Medium
Wave frequencies.
Transmission line should also be matched at the receiver end?
100 feet of coax at those frequencies should have low loss?

You never mention how far away you are from "... Indianapolis 1070kc and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

I'm 70mi from Indy and 120mi from Chicago. Chicago 670kc is reasonable at
night 1070kc out of Indy at night is pretty bad.
Is 40ft at right angles to these signals better that 200ft parallel?

Terry wrote:

One wavelength at a frequency of say 1070 kcs is a little less than 300
metres (approx 1000 feet?).
An antenna of either length will be very 'short' compared to the
'wavelengths' involved and will not be close to resonance.
e.g. For quarter wave resonance (approx 75 metres or about 250 feet; for
1070 kcs and nearly 400 feet for say 670 kcs ) required.
Any 'too short' antenna will be will be badly mismatched (energy loss!) to
the impedance of the co-ax.
This suggest that some kind of untuned impedance matching transformer,
suitable for the frequencies in question, might be used to transfer as
much energy as possible to the co-ax transmission line?
Seen this done with short 'whip' antenna operating at Broadcast
Band/Medium Wave frequencies.
Transmission line should also be matched at the receiver end?
100 feet of coax at those frequencies should have low loss?

any guidance on how I accomplish above impedance matching

thanks in advance
jeff

In article ,
"Jeff Dieterle" writes:
You never mention how far away you are from "... Indianapolis 1070kc and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

I'm 70mi from Indy and 120mi from Chicago. Chicago 670kc is reasonable at
night 1070kc out of Indy at night is pretty bad.
Is 40ft at right angles to these signals better that 200ft parallel?

(This doesn't solve your problem, but might give you some info as to
why the reception of WIBC is somewhat difficult.)

Given your distances, then you are somewhere between Indy and Chicago.

WIBC drops their power significantly at night, and also the antenna
pattern shows that the available signal is probably the worst possible
given the antenna :-(. Here is a picture of the WIBC pattern, and
consider the WIBC towers are on the NW side of Indy.

http://www.fcc.gov/Bureaus/MB/Databa...06964-6786.pdf

John

"John S. Dyson" wrote in message
...
In article ,
"Jeff Dieterle" writes:
You never mention how far away you are from "... Indianapolis 1070kc
and
Chicago 670kc & 1000kc." That'll have a LARGE bearing on the
day/night
reception question.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

I'm 70mi from Indy and 120mi from Chicago. Chicago 670kc is reasonable at
night 1070kc out of Indy at night is pretty bad.
Is 40ft at right angles to these signals better that 200ft parallel?

(This doesn't solve your problem, but might give you some info as to
why the reception of WIBC is somewhat difficult.)

Given your distances, then you are somewhere between Indy and Chicago.

WIBC drops their power significantly at night, and also the antenna
pattern shows that the available signal is probably the worst possible
given the antenna :-(. Here is a picture of the WIBC pattern, and
consider the WIBC towers are on the NW side of Indy.

http://www.fcc.gov/Bureaus/MB/Databa...06964-6786.pdf

John

Ya, I see they drop their signal strength from 50kw to 10kw at night. What
would be the best antenna design for this station. I've considered buying a
tuned loop for this frequency but I'm reluctant to drop $70 and maybe not do
any better than my straightwire.

Jeff Dieterlle wrote:
"I ran RG 6-U coax to the roof of the factory (approx. 100 ft) and
considered buying a loop antenna but at this group`s suggestion
connected the coax to the long wire. The stations I`m interested in are
Indianapolis 1070 kc and Chicago 670 kc & 1000 kc. I installed 200 ft of
#12 ga insulated wire that is oriented in line with these 2 cities
and....."

Jeff didn`t say how far he is from the stations. All 3 stations run 50
KW but have daytime directional patterns which may affect the signal
strength he receives.

50 KW nondirectional can produce 1860 millivolts per meter at one mile
or 9.3 millivolts at 200 miles. I said may because it depends on ground
conductiviyty and other factors. I listen to to a 50 KW station 200
miles away 24 hours.

RG-6 has a capacitnance of 20.5pF/ft. So, 100 ft. totals 2050 pF. At
1000 KHz, its reactance is about 78 ohms. This is shunting the impedance
of 61 meters of 12 gauge wire (0.0033 WL), a fairly figh capacitive
reactance at 1000 KHz. This is a voltage divider. Most of the energy
captured by the wire is dropped scross the wire and reradiated never
reaching the receiver. That was why a loop which matched the coax was
suggested.. Jeff pribably gets enough signal in his antenna. He might
get more of it to his receiver using a broadband transformer between his
antenna and coax which stepped doown the impedance to match the coax
approximately. He may need to step it back up at the receiver end. I
recall using this arrangement in 1938 with a General Electric all-band
doublet kit and it worked well.

Pointing the wire at the station is fine for a Beverage antenna but
about 2 wavelengths is needed for a Beverage.. That wold be 1968 feet at
1000 KHz. The Beverage is vertically polarized, as needed to receive a
ground wave. Otherwise, shorter antennas may do better at a more
broadside attitude towards the signal wavefront. A random wire generally
uses its vertical component to receive groundwaves.

Best regards, Richard Harriison, KB5WZI

thanks for all the help, I'll start researching an impedance matching
transformer for my setup, I guess I'll probably need to wind a balun to
match the antenna and coax


"Richard Harrison" wrote in message
...
Jeff Dieterlle wrote:
"I ran RG 6-U coax to the roof of the factory (approx. 100 ft) and
considered buying a loop antenna but at this group`s suggestion
connected the coax to the long wire. The stations I`m interested in are
Indianapolis 1070 kc and Chicago 670 kc & 1000 kc. I installed 200 ft of
#12 ga insulated wire that is oriented in line with these 2 cities
and....."

Jeff didn`t say how far he is from the stations. All 3 stations run 50
KW but have daytime directional patterns which may affect the signal
strength he receives.

50 KW nondirectional can produce 1860 millivolts per meter at one mile
or 9.3 millivolts at 200 miles. I said may because it depends on ground
conductiviyty and other factors. I listen to to a 50 KW station 200
miles away 24 hours.

RG-6 has a capacitnance of 20.5pF/ft. So, 100 ft. totals 2050 pF. At
1000 KHz, its reactance is about 78 ohms. This is shunting the impedance
of 61 meters of 12 gauge wire (0.0033 WL), a fairly figh capacitive
reactance at 1000 KHz. This is a voltage divider. Most of the energy
captured by the wire is dropped scross the wire and reradiated never
reaching the receiver. That was why a loop which matched the coax was
suggested.. Jeff pribably gets enough signal in his antenna. He might
get more of it to his receiver using a broadband transformer between his
antenna and coax which stepped doown the impedance to match the coax
approximately. He may need to step it back up at the receiver end. I
recall using this arrangement in 1938 with a General Electric all-band
doublet kit and it worked well.

Pointing the wire at the station is fine for a Beverage antenna but
about 2 wavelengths is needed for a Beverage.. That wold be 1968 feet at
1000 KHz. The Beverage is vertically polarized, as needed to receive a
ground wave. Otherwise, shorter antennas may do better at a more
broadside attitude towards the signal wavefront. A random wire generally
uses its vertical component to receive groundwaves.

Best regards, Richard Harriison, KB5WZI