Tim,

One thing you will want to check before running your antenna wire on the roof
is the possibility of any electrical service wiring running in the attic. It
may be that if you have AC wiring in close proximity to the antenna, especially
running parallel to it, you could pick up some line noise on your antenna feed.


Ken Maltz
Jericho, NY
NRD-535D, NRD-220 Collins R-388, Racal RA6790/GM,
ICOM R71A, ICOM R-7100(x2), AOR AR-8000
Panasonic RF-2200, Sony ICF-7600GR,
Hoka Code3 Gold-Pro, 60' long wire, MLB balun

KM,

What you say/wrote about electical wiring in the Attic is very true.
- - - Especially if you have any major electrical equipment mounted in
the Attic or on the Roof. Air Conditioners, Fans, ETC.

For Attic Electrical Wiring and Noise
(When the only place you can put an Antenna is in the Attic.)
- - - Think Horizontal Loop Antenna

IMHO: The best type of 'antenna' to use in the Attic is a Horizontal
Loop Antenna. Loops generally have lower/less man made noise pick-up.

* Mount it at least 3-6 Feet above the Attic Floor and follow the
Primeter of the Roof.
NOTE: This has to be a compromise Height vice Size.

* Use a Matching Transformer in the Attic and a Coax FeedLine from the
Attic down to the Radio. (More Noise Reduction.)


iane ~ RHF
..
..
= = = (Ken Maltz)
= = = wrote in message ...
Tim,

One thing you will want to check before running your antenna wire on the roof
is the possibility of any electrical service wiring running in the attic. It
may be that if you have AC wiring in close proximity to the antenna, especially
running parallel to it, you could pick up some line noise on your antenna feed.


Ken Maltz
Jericho, NY
NRD-535D, NRD-220 Collins R-388, Racal RA6790/GM,
ICOM R71A, ICOM R-7100(x2), AOR AR-8000
Panasonic RF-2200, Sony ICF-7600GR,
Hoka Code3 Gold-Pro, 60' long wire, MLB balun

Yes RHF, this is an excellent suggestion; as is using a balun matched length of
coax as lead in cable. I fould that replacing my single wire lead in with the
MLB balun and good quality coax eliminated at least 90% of man-made electrical
noise on my antenna.
Ken Maltz
Jericho, NY
NRD-535D, NRD-220 Collins R-388, Racal RA6790/GM,
ICOM R71A, ICOM R-7100(x2), AOR AR-8000
Panasonic RF-2200, Sony ICF-7600GR,
Hoka Code3 Gold-Pro, 60' long wire, MLB balun

RHF wrote:

KM,

What you say/wrote about electical wiring in the Attic is very true.
- - - Especially if you have any major electrical equipment mounted in
the Attic or on the Roof. Air Conditioners, Fans, ETC.

For Attic Electrical Wiring and Noise
(When the only place you can put an Antenna is in the Attic.)
- - - Think Horizontal Loop Antenna

IMHO: The best type of 'antenna' to use in the Attic is a Horizontal
Loop Antenna. Loops generally have lower/less man made noise pick-up.

* Mount it at least 3-6 Feet above the Attic Floor and follow the
Primeter of the Roof.
NOTE: This has to be a compromise Height vice Size.

* Use a Matching Transformer in the Attic and a Coax FeedLine from the
Attic down to the Radio. (More Noise Reduction.)

iane ~ RHF

What would the typical impedance be for such a (horizontal) loop?
Would it improve reception to make the section of the loop opposite the
feed point go vertically up the attic's gable-end wall to the ridge
peak?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

= = = starman
= = = wrote in message ...
RHF wrote:

KM,

What you say/wrote about electical wiring in the Attic is very true.
- - - Especially if you have any major electrical equipment mounted in
the Attic or on the Roof. Air Conditioners, Fans, ETC.

For Attic Electrical Wiring and Noise
(When the only place you can put an Antenna is in the Attic.)
- - - Think Horizontal Loop Antenna

IMHO: The best type of 'antenna' to use in the Attic is a Horizontal
Loop Antenna. Loops generally have lower/less man made noise pick-up.

* Mount it at least 3-6 Feet above the Attic Floor and follow the
Primeter of the Roof.
NOTE: This has to be a compromise Height vice Size.

* Use a Matching Transformer in the Attic and a Coax FeedLine from the
Attic down to the Radio. (More Noise Reduction.)

iane ~ RHF

What would the typical impedance be for such a (horizontal) loop?
Would it improve reception to make the section of the loop opposite the
feed point go vertically up the attic's gable-end wall to the ridge
peak?



Starman,

Until One Builds It - IT Is An Unknown.
* It is my understanding that this would be a "Receive Only" Antenna.
* The Impedance may range from 100 - 400 Ohms.
* A 1:4 Balun would most likely work will with this In-the-Attic
Antenna.
* Most likely the feed point would be where you cound get the most
direct access for the FeedLine.
* * However, YES - The FeedPoint could be 'located' and the Antenna
Wire 'configured' to improve reception and directivity.
NOTE: Some type of Antenna Tester would be necessary if your were
going to play with the wire to improve the reception and directivity
qualities.

About Roofs:
* Not All Roofs are Peaked - Some are Flat.
* Not All Roof are Squares/Rectangles - Some are "L" Shaped and other.
* * Some Roofs are made of metal :-(


OBTW: As I was writing this and thinking of the possible shapes
within the confines of an Attic; the SpiderWire Antenna came to mind.
= = = http://www.coneantenna.com/Drawings.htm
- - - A form of Double Loop Dipole.
* If you have a Rectangler High Peaked Roof.
* The Feed Point of the Antenna could be mounted at the Center of the
Rectangle and the Peak of the Roof.
* The Four Legs would then be routed down to the bottom corners of the
Roof.
* The Leg ends would then be routed flat with the eaves
* * OR - The Leg Ends could be routed up & down the Attic's gable-end
walls in an Inverted "V".


iane ~ RHF
..
GoTo= http://groups.yahoo.com/group/SWL-AM-FM-Antenna/
..