Frnak McKenney wrote:


Robert,

Thank you for joining in.

On Tue, 09 Oct 2007 22:35:29 -0700, Robert Smts wrote:
Frnak McKenney wrote:
I'm in Richmond, Virginia and I'm trying to noticeably improve my
reception of WWV's 10MHz signal from Fort Collins, Colorado. It all
seemed so simple, two weeks ago: wind some wire, solder a
connector, and Hey...presto! a clean WWV signal. grin!
--snip--

Frank, can't you erect anything outside at all? A 10 metre dipole,
is after all, only about 5 metres long. And if you can't do that,
what kind of attic do you have? If your house is oriented
correctly, you could even build a three element wire yagi pointed
west inside the attic.

Um... 10m? I was hoping for 10MHz/30m. Or have I missed
something? (Wouldn't surprise me -- my 1st Class ticket expired
several decades back.)

HMMMM. I was having a blonde moment, I think. Of course I meant 10 MHz and
not 10 Metres. The dimensions were correct, though for 10 MHz. Looks like
one of those days where the brain fades...

Okay... ARRL Antennas, Chapter 8: Multielement Arrays. We've got
an (approximately, given skip) vertically-polarized 10MHz signal, so
the E-field is moving up and down and the wavefront is a circular
ripple (nearly a straight line by the time it gets to Richmond)
travelling roughly west-to-east, that is, it's hitting my house
end-on.

Dimensions shouldn't be that critical for receive only, and space
the elements at about 2.5 metres. Basically one element at about 47
feet, one at about 49.3 feet, and one at about 45 feet. Split the
47 ft one into two, feed it directly with 50 ohm coax, one side to
the shield, one to the centre conductor, and you have a three
element wire beam pointed, hopefully, west. (Put the longest
element on the east side, the shortest on the west.)

Um... if I label them as A/47ft, B/49ft, and C/45ft, the picture I
come up with looks like this from overhead:

| | |
| | |
--- To Fort Collins | + |
| + |
| | |
| | |
(scale)
|............................................C.A.B


I definitely think I'm missing something, but then, I haven't really
made it that far into the Antenna Handbook.

Anyway, thanks for the suggestion.

You're welcome. Your characterisation of the antenna as above is correct,
and hopefully your attic is correctly oriented. Of course if you can put it
outside, fixed wire beams are often very useful.


Frank
--
"Our Constitution is in actual operation; everything appears to
promise that it will last; but in this world nothing is certain
but death and taxes." -- Benjamin Franklin
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

On Thu, 11 Oct 2007 11:21:29 -0700, Robert Smts wrote:
Frnak McKenney wrote:
--snip--
On Tue, 09 Oct 2007 22:35:29 -0700, Robert Smts wrote:
Frnak McKenney wrote:
I'm in Richmond, Virginia and I'm trying to noticeably improve my
reception of WWV's 10MHz signal from Fort Collins, Colorado.
--snip--

Frank, can't you erect anything outside at all? A 10 metre dipole,
is after all, only about 5 metres long. And if you can't do that,
what kind of attic do you have? If your house is oriented
correctly, you could even build a three element wire yagi pointed
west inside the attic.
--snip--
I definitely think I'm missing something, but then, I haven't really
made it that far into the Antenna Handbook.

Anyway, thanks for the suggestion.

You're welcome. Your characterisation of the antenna as above is correct,
and hopefully your attic is correctly oriented. Of course if you can put it
outside, fixed wire beams are often very useful.

If I'm following the ARRL handbook correctly, I want the elements
laid out _across_ the incoming wavefront. For Fort Collins to
Richmond, that is, going west to east, that would mean I'd want to
string the wires/elements north-south. Naturally (per Murphy, the
patron saint of Data Processing) my house is oriented E-W. Which
does still, as you point out, leave the possibility of building
something outdoors.

Still, my current indoor loop seems to be picking up a nice strong
signal. It was upright when I first started testing, but it wound up
being laid flat at some point in the past few days -- about the time
I discovered that I had been mis-tuining it. Wonder which had more
effect: my changes, or atmospherics? grin!

Anyway, thank you for your time and suggestions. I did some looking
around on the 'web for introductory material to help me understand
the ARRL Antenna Handbook and stumbled onto these:

Antenna Newcomers and the Language of Antennas
http://www.cebik.com/tales/nc.html

Antennas from the Ground Up
http://www.cebik.com/gup/groundup.html

Some really nice propagation plots. Now, if there were just some
simple way of figuring out which way the antenna is oriented
relative to the plots... "It's an imperfect universe" grin!


Frank
--
Anyone who is not genuinely addicted to the search for knowledge
is unlikely to have the psychological energy to be a true scholar
in any field. But in history this work clearly resembles more
that of a detective than that of a scientist -- a search for and
judgment of particular evidence rather than a repeatable
experiment. The detective side of historical research needs
skill, background, and intuition.
-- Robert Conquest, "The Dragons of Expectation"
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)

Frnak McKenney wrote:

If I'm following the ARRL handbook correctly, I want the elements
laid out _across_ the incoming wavefront. For Fort Collins to
Richmond, that is, going west to east, that would mean I'd want to
string the wires/elements north-south. Naturally (per Murphy, the
patron saint of Data Processing) my house is oriented E-W. Which
does still, as you point out, leave the possibility of building
something outdoors.

You're following it correctly only if you're using elements which are no
longer than about 5/4 wavelength. The direction of maximum gain isn't
longer perpendicular to the wire if the wire is longer. This is covered
very will in the _Antenna Book_.

Still, my current indoor loop seems to be picking up a nice strong
signal. It was upright when I first started testing, but it wound up
being laid flat at some point in the past few days -- about the time
I discovered that I had been mis-tuining it. Wonder which had more
effect: my changes, or atmospherics? grin!

As I mentioned in my other recent posting, there's no way for you to tell.

Anyway, thank you for your time and suggestions. I did some looking
around on the 'web for introductory material to help me understand
the ARRL Antenna Handbook and stumbled onto these:

Antenna Newcomers and the Language of Antennas
http://www.cebik.com/tales/nc.html

Antennas from the Ground Up
http://www.cebik.com/gup/groundup.html

Some really nice propagation plots. Now, if there were just some
simple way of figuring out which way the antenna is oriented
relative to the plots... "It's an imperfect universe" grin!

You can duplicate the plots for the kinds of simple antennas you're
dealing with, with the free demo version of EZNEC available from
http://eznec.com. In the View Antenna display, select View/Objects, then
check the "2D Display" box. Then you'll see a 2D plot superimposed on
the view of the antenna, to show how the two are related. When viewing a
3D plot, the View Antenna display rotates along with the 3D pattern, so
you can see how they're related if you keep both windows open.

Roy Lewallen, W7EL

On Sun, 14 Oct 2007 17:20:32 -0700, Roy Lewallen wrote:
Frnak McKenney wrote:
--snip--
Still, my current indoor loop seems to be picking up a nice strong
signal. It was upright when I first started testing, but it wound up
being laid flat at some point in the past few days -- about the time
I discovered that I had been mis-tuining it. Wonder which had more
effect: my changes, or atmospherics? grin!

As I mentioned in my other recent posting, there's no way for you to tell.

I noticed. Yesterday all those really clear tones and voice
segments vanished while I wasn't paying attention. I can still hear
enough WWV on occasion to know it's still there, but it's not even
close to being strong enough to start the clock running.

Anyway, thank you for your time and suggestions. I did some looking
around on the 'web for introductory material to help me understand
the ARRL Antenna Handbook and stumbled onto these:

Antenna Newcomers and the Language of Antennas
http://www.cebik.com/tales/nc.html

Antennas from the Ground Up
http://www.cebik.com/gup/groundup.html

Some really nice propagation plots. Now, if there were just some
simple way of figuring out which way the antenna is oriented
relative to the plots... "It's an imperfect universe" grin!

You can duplicate the plots for the kinds of simple antennas you're
dealing with, with the free demo version of EZNEC available from
http://eznec.com. In the View Antenna display, select View/Objects, then
check the "2D Display" box. Then you'll see a 2D plot superimposed on
the view of the antenna, to show how the two are related. When viewing a
3D plot, the View Antenna display rotates along with the 3D pattern, so
you can see how they're related if you keep both windows open.

Thanks for the pointer; I didn't knwo that there was a free version
available. I'll check it out when I get a chance


Frank
--
"Don't be afraid to take a big step if one is indicated.
You can't cross a chasm in two small jumps."
-- David Lloyd George, British Statesman
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)