In article ,
Jim Thompson wrote:
[....]

But I vaguely recall a 5/8 wavelength antenna that had a good
low-angle pattern.

Unfortunately, the OP (is he still here?) was stuck with a box to short to
even fit a 1/4 wave whip. I also think that this box could not be assumed
to be resting on the ground


If you squint at the ASCII art below, you will see more or less the
radiation pattern of a 5/8 whip over a large ground plain.
.................................
.................!...............
...........******!*****..........
..........*......!......*........
..........*......!......*........
...........****..!..****...A.....
........*******..!..*******......
.....***.........!.........***...
...*.............!.............*B
********************************

If you don't have a large enough ground plain, the notch in the side
labeled "A" starts to go away and the peak at "B" reduces.


--
--
forging knowledge

On Sun, 27 Feb 2005 17:52:52 +0000 (UTC),
(Ken Smith) wrote:

In article ,
Jim Thompson wrote:
[....]

But I vaguely recall a 5/8 wavelength antenna that had a good
low-angle pattern.

Unfortunately, the OP (is he still here?) was stuck with a box to short to
even fit a 1/4 wave whip. I also think that this box could not be assumed
to be resting on the ground


If you squint at the ASCII art below, you will see more or less the
radiation pattern of a 5/8 whip over a large ground plain.
................................
................!...............
..........******!*****..........
.........*......!......*........
.........*......!......*........
..........****..!..****...A.....
.......*******..!..*******......
....***.........!.........***...
..*.............!.............*B
********************************

If you don't have a large enough ground plain, the notch in the side
labeled "A" starts to go away and the peak at "B" reduces.


--

The rain in Spain falls mainly on the plain ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Still here, not quite sure who to believe, but enjoying the ride :-)

On 27 Feb 2005 18:05:36 -0800, wrote:

Still here, not quite sure who to believe, but enjoying the ride :-)

Hi OM,

The long and short of it (apropos of your antenna spec), is that your
shorter antenna will need a new matching circuit (apropos of the
smaller antenna's size) for the related issues of maximum transfer of
power. The reasons for matching may vary (and with it, efficiency),
but not so you would notice. If you did notice, then your production
tolerance (if not customer application) variations will kill you in
the marketplace (fact of life in a Kapitalistic world). No amount of
armchair philosophies about Thevenin's theorem will replace that loss.

73's
Richard Clark, KB7QHC

Richard Clark wrote:


No amount of armchair philosophies about
Thevenin's theorem will replace that loss.

Thevenin's is a linear theorem. Large signal devices are not linear. (Hey,
maybe triodes are, but I don't use them for PA's.)

There is no armchair philosophy about Thevenin's theorem because it does not
apply in the RF PA situation. Your's is a red herring.