Why does the Lazy H antenna suck in the real world on 11 meters?
 

On Jul 5, 12:42 pm, Michael wrote:
I've seen the Lazy H mentioned in many antenna books over the years,
so I decided to try one on 10 meters. According to the ARRL handbook
the Lazy H is two collinear elements stacked on above the other, Each
collinear element is made up of two 1/2 wave elements. I chose to
use 5/8 wave spacing between the top and bottom elements. I connected
the top and bottom elements with 450 ohm 16 gauge stranded ladder line
(window line). After building the antenna I verified connectivity
between the top and bottom right elements and the top and bottom left
elements. I color coded the end insulators on each side so I could
easily see which top and bottom elements were connected to each other.
The antenna book says to connect the 450 ohm ladder line from the
antenna tuner to the middle of the 450 ladder line that connects top
and bottom elements. Ok done. Now I put up the antenna and make sure
the top and bottom elements are in phase. That is both left connected
elements are on the left and both right connected element are on the
right. I also make sure there is no twist in the ladder line
connecting the top and bottom elements. I also checked the other
ends of the 450 ohm ladder line feeding the antenna has connectivity
at the antenna, and the left and right sides of the ladder line do not
have connectivity. The 450 ohm ladder line feeding the antenna is
about 200 feet long.
Now I bring the 450 ohm feedline in to the house, hook it to my
Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up,
and it sucks! Both my half wave horizontal dipole and my Solarcon
Max-2000 blow it away on incoming skip even in the preferred direction
of the lazy H. I rechecked my connections and the lengths of the
elements and spacing and they are correct. I did take in to account
the velocity factor of the 450 ladder line that connects the top
elements to the bottom elements. The antenna book says the length of
the 450 ladder lien between the antenna and the antenna tuner can e
any lenght.
The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong?

Michael

I found an article that shows using a 1/4 wave matching stub at the
bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even
ladder line transmission line needs a matching stub.

http://www.ve7zsa.net/technical/advs...ntenna_r00.htm

Why does the Lazy H antenna suck in the real world on 11 meters?
 

On Jul 6, 1:55 pm, Michael wrote:
On Jul 5, 12:42 pm, Michael wrote:



I've seen the Lazy H mentioned in many antenna books over the years,
so I decided to try one on 10 meters. According to the ARRL handbook
the Lazy H is two collinear elements stacked on above the other, Each
collinear element is made up of two 1/2 wave elements. I chose to
use 5/8 wave spacing between the top and bottom elements. I connected
the top and bottom elements with 450 ohm 16 gauge stranded ladder line
(window line). After building the antenna I verified connectivity
between the top and bottom right elements and the top and bottom left
elements. I color coded the end insulators on each side so I could
easily see which top and bottom elements were connected to each other.
The antenna book says to connect the 450 ohm ladder line from the
antenna tuner to the middle of the 450 ladder line that connects top
and bottom elements. Ok done. Now I put up the antenna and make sure
the top and bottom elements are in phase. That is both left connected
elements are on the left and both right connected element are on the
right. I also make sure there is no twist in the ladder line
connecting the top and bottom elements. I also checked the other
ends of the 450 ohm ladder line feeding the antenna has connectivity
at the antenna, and the left and right sides of the ladder line do not
have connectivity. The 450 ohm ladder line feeding the antenna is
about 200 feet long.
Now I bring the 450 ohm feedline in to the house, hook it to my
Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up,
and it sucks! Both my half wave horizontal dipole and my Solarcon
Max-2000 blow it away on incoming skip even in the preferred direction
of the lazy H. I rechecked my connections and the lengths of the
elements and spacing and they are correct. I did take in to account
the velocity factor of the 450 ladder line that connects the top
elements to the bottom elements. The antenna book says the length of
the 450 ladder lien between the antenna and the antenna tuner can e
any lenght.
The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong?

Michael

I found an article that shows using a 1/4 wave matching stub at the
bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even
ladder line transmission line needs a matching stub.

http://www.ve7zsa.net/technical/advs...ntenna_r00.htm

Looks like another user had similar problems with a Lazy H using 450
ladder line all the way to the tuner. Like me his will tune on 14 MHz
where it is basically stacked dipoles, but once you get to 10 meters
it is a no go. He tried 450 ohm ladder line to a balun as well.

http://forums.qrz.com/archive/index.php/t-135914.html

Why does the Lazy H antenna suck in the real world on 11 meters?
 

On Jul 6, 1:55 pm, Michael wrote:
On Jul 5, 12:42 pm, Michael wrote:



I've seen the Lazy H mentioned in many antenna books over the years,
so I decided to try one on 10 meters. According to the ARRL handbook
the Lazy H is two collinear elements stacked on above the other, Each
collinear element is made up of two 1/2 wave elements. I chose to
use 5/8 wave spacing between the top and bottom elements. I connected
the top and bottom elements with 450 ohm 16 gauge stranded ladder line
(window line). After building the antenna I verified connectivity
between the top and bottom right elements and the top and bottom left
elements. I color coded the end insulators on each side so I could
easily see which top and bottom elements were connected to each other.
The antenna book says to connect the 450 ohm ladder line from the
antenna tuner to the middle of the 450 ladder line that connects top
and bottom elements. Ok done. Now I put up the antenna and make sure
the top and bottom elements are in phase. That is both left connected
elements are on the left and both right connected element are on the
right. I also make sure there is no twist in the ladder line
connecting the top and bottom elements. I also checked the other
ends of the 450 ohm ladder line feeding the antenna has connectivity
at the antenna, and the left and right sides of the ladder line do not
have connectivity. The 450 ohm ladder line feeding the antenna is
about 200 feet long.
Now I bring the 450 ohm feedline in to the house, hook it to my
Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up,
and it sucks! Both my half wave horizontal dipole and my Solarcon
Max-2000 blow it away on incoming skip even in the preferred direction
of the lazy H. I rechecked my connections and the lengths of the
elements and spacing and they are correct. I did take in to account
the velocity factor of the 450 ladder line that connects the top
elements to the bottom elements. The antenna book says the length of
the 450 ladder lien between the antenna and the antenna tuner can e
any lenght.
The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong?

Michael

I found an article that shows using a 1/4 wave matching stub at the
bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even
ladder line transmission line needs a matching stub.

http://www.ve7zsa.net/technical/advs...ntenna_r00.htm

Yep. Looks like that is it. Unfortunately I am out of time for this
weekend, so I'll have to try it out next weekend. According to an
article I found I need a closed end 1/4 matching stub. I'll update
here after I try it out next weekend.

-Michael

Why does the Lazy H antenna suck in the real world on 11 meters?
 

The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong?

I suspect with your long feedline length (200 ft you said?), and the
probably very high SWR on the feedline, you have significant feedline loss.

Also, are the elements really horizontal? Or are they closer to inverted V's?

Tor
N4OGW

Why does the Lazy H antenna suck in the real world on 11 meters?
 

Michael wrote in news:e4ae9836-71d2-4075-9823-
:

I've seen the Lazy H mentioned in many antenna books over the years,
so I decided to try one on 10 meters. According to the ARRL handbook
the Lazy H is two collinear elements stacked on above the other, Each
collinear element is made up of two 1/2 wave elements. I chose to
use 5/8 wave spacing between the top and bottom elements. I connected
the top and bottom elements with 450 ohm 16 gauge stranded ladder line
(window line). After building the antenna I verified connectivity
between the top and bottom right elements and the top and bottom left
elements. I color coded the end insulators on each side so I could
easily see which top and bottom elements were connected to each other.
The antenna book says to connect the 450 ohm ladder line from the
antenna tuner to the middle of the 450 ladder line that connects top
and bottom elements. Ok done. Now I put up the antenna and make sure
the top and bottom elements are in phase. That is both left connected
elements are on the left and both right connected element are on the
right. I also make sure there is no twist in the ladder line
connecting the top and bottom elements. I also checked the other
ends of the 450 ohm ladder line feeding the antenna has connectivity
at the antenna, and the left and right sides of the ladder line do not
have connectivity. The 450 ohm ladder line feeding the antenna is
about 200 feet long.
Now I bring the 450 ohm feedline in to the house, hook it to my
Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up,
and it sucks! Both my half wave horizontal dipole and my Solarcon
Max-2000 blow it away on incoming skip even in the preferred direction
of the lazy H. I rechecked my connections and the lengths of the
elements and spacing and they are correct. I did take in to account
the velocity factor of the 450 ladder line that connects the top
elements to the bottom elements. The antenna book says the length of
the 450 ladder lien between the antenna and the antenna tuner can e
any lenght.
The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong?

Have you tried lengthening or shortening the line by about 4 1/2 feet?
It may be simply that the length of the line is resulting in an impedance
your tuner cannot match.

I think, given the nature of the antenna and the length of your line, you
can probably expect about 3 dB losses on a dry line and close to 10 on a
wet one.



--
Dave Oldridge+
ICQ 1800667
VA7CZ