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.