Final verdict on the center fed Lazy H antenna for 10 meters...

I really wanted to like this antenna. I really wanted it to work as
stated in the various handbooks. I have checked and re-checked the
measurements, and I have double checked the connectivity to make sure
the top and bottom elements were being fed in phase. The bottom left
element was connected to the top left element. The bottom right
element was connected to the top right element. I have done countless
A/B/C test with a dipole, an extended double zepp, and the Lazy H all
broadside to the same direction on 10 meters. This antenna was
specifically cut for 10 meters, and it was installed for horizontal
polarization as shown in the ARRL handbook at heights of 40 feet and
50 feet at the top wire. I double checked everything, but the final
verdict is not what I had hoped.

Here it is;

In the real world on 10 meters the Lazy H antenna with four half wave
elements on 10 meters (two collinear elements on top and two collinear
elements on the bottom), half wave spacing between the top and bottom
horizontal elements, center fed with 450 ladder line all the way back
to the antenna tuner, using a 450 ohm ladder line phasing line to
connect the top and bottom elements with no twist was consistently out
performed by a 10 meter extended double zepp facing the same direction
even when the Lazy H antenna was given a 10 foot height advantage over
the extended double zepp. On many occasions the Lazy H was also out
performed by the 10 meter dipole dipole. I have not tried the end fed
Lazy H design with the 1/4 wave matching stub and the 180 degree twist
in the phasing line.

On a positive note, the extended double zepp antenna with a 450 ohm
matching section down to a 1:1 balun and then 50 ohm coax is a solid
performer, and it consistently out performs a dipole and the Lazy H
broadside to the antenna.

Michael Rawls
KS4HY

On 6/4/2011 7:04 AM, Michael wrote:

...
On a positive note, the extended double zepp antenna with a 450 ohm
matching section down to a 1:1 balun and then 50 ohm coax is a solid
performer, and it consistently out performs a dipole and the Lazy H
broadside to the antenna.

Michael Rawls
KS4HY

You are "matching" 450 ohm line to 50 ohm coax thru a 1:1 balun?

Where is the matchbox/tuner located?

--

Regards,
JS
“The Constitution is not an instrument for the government to restrain
the people, it’s an instrument for the people to restrain the
government.” -- Patrick Henry

On 6/4/2011 7:30 AM, John Smith wrote:
On 6/4/2011 7:04 AM, Michael wrote:

...
On a positive note, the extended double zepp antenna with a 450 ohm
matching section down to a 1:1 balun and then 50 ohm coax is a solid
performer, and it consistently out performs a dipole and the Lazy H
broadside to the antenna.

Michael Rawls
KS4HY

You are "matching" 450 ohm line to 50 ohm coax thru a 1:1 balun?

Where is the matchbox/tuner located?


Never mind, should have read your post closer, you are claiming to have
already handled it in the "450 ohm matching section."

--

Regards,
JS
“The Constitution is not an instrument for the government to restrain
the people, it’s an instrument for the people to restrain the
government.” -- Patrick Henry

On Sat, 4 Jun 2011 07:04:28 -0700 (PDT), Michael
wrote:

but the final
verdict is not what I had hoped.
probably because it is unbalanced by being connected:
to the antenna tuner
which through its ground connection unbalances the Lazy H.

For the entire duration of your discussion, I've seen no treatment for
common mode problems that you have described by various symptoms in
the past. Your complaint of poor performance is a chief indicator.

Other indications have ranged variably from glaring beyond that to not
apparent yet remaining a problem still, as is obvious by the poor gain
performance for all variations.

You already have the solution in the other antenna:
a 1:1 balun and then 50 ohm coax is a solid
performer
provided the BalUn is a W2DU.

Your problem is NOT the antenna!

73's
Richard Clark, KB7QHC

On Jun 4, 11:42*am, Richard Clark wrote:
On Sat, 4 Jun 2011 07:04:28 -0700 (PDT), Michael

wrote:
but the final
verdict is not what I had hoped.

probably because it is unbalanced by being connected:to the antenna tuner

which through its ground connection unbalances the Lazy H.

For the entire duration of your discussion, I've seen no treatment for
common mode problems that you have described by various symptoms in
the past. *Your complaint of poor performance is a chief indicator.

Other indications have ranged variably from glaring beyond that to not
apparent yet remaining a problem still, as is obvious by the poor gain
performance for all variations.

You already have the solution in the other antenna: a 1:1 balun and then 50 ohm coax is a solid
performer

provided the BalUn is a W2DU.

Your problem is NOT the antenna!

73's
Richard Clark, KB7QHC

The tuners I have both have built in baluns. After I took down the
Lazy H I put up a delta loop with 300 ohm twin lead back to the same
balanced line tuner connections. The delta loop out performed the
dipole by a hair, but the delta loop has a height advantage over the
dipole.

I have some other baluns lying around. I suppose I could hook the
450 ladder line to one of those baluns and then connect a coax jumper
between it and the antenna tuner and try it. It seems like they may
be W2AU baluns. I bought them back in the 1990s, but I have not looked
at the labels in awhile.

I still may try the end fed Lazy H with the twist.

Michael

On Jun 4, 9:10*pm, Michael wrote:
On Jun 4, 11:42*am, Richard Clark wrote:



On Sat, 4 Jun 2011 07:04:28 -0700 (PDT), Michael

wrote:
but the final
verdict is not what I had hoped.

probably because it is unbalanced by being connected:to the antenna tuner

which through its ground connection unbalances theLazyH.

For the entire duration of your discussion, I've seen no treatment for
common mode problems that you have described by various symptoms in
the past. *Your complaint of poor performance is a chief indicator.

Other indications have ranged variably from glaring beyond that to not
apparent yet remaining a problem still, as is obvious by the poor gain
performance for all variations.

You already have the solution in the other antenna: a 1:1 balun and then 50 ohm coax is a solid
performer

provided the BalUn is a W2DU.

Your problem is NOT the antenna!

73's
Richard Clark, KB7QHC

The tuners I have both have built in baluns. After I took down theLazyH I put up a delta loop with 300 ohm twin lead back to the same
balanced line tuner connections. *The delta loop out performed the
dipole by a hair, but the delta loop has a height advantage over the
dipole.

I have some other baluns lying around. * I suppose I could hook the
450 ladder line to one of those baluns and then connect a coax jumper
between it and the antenna tuner and try it. *It seems like they may
be W2AU baluns. I bought them back in the 1990s, but I have not looked
at the labels in awhile.

I still may try the end fedLazyHwith the twist.

Michael

I just remembered most of those external baluns are 1:1 baluns. I do
have one external commercial 4:1 balun, and one 4:1 balun I hand wound
from a schematic in one of my antenna books.

-Michael

On Sat, 4 Jun 2011 19:38:55 -0700 (PDT), Michael
wrote:

I just remembered most of those external baluns are 1:1 baluns. I do
have one external commercial 4:1 balun, and one 4:1 balun I hand wound
from a schematic in one of my antenna books.

Hi Michael,

The odds are that the BalUns you wound are similar to the ones in your
tuner(s) - and they will NOT do the job properly.

By properly, the BalUn MUST choke the line. This comes for free with
the W2DU style, as there is only one way to build one, the right way.

The distinction is between what are called voltage BalUns and current
BalUns. Frequently, web sites that purport to know the difference
DON'T know the difference. The W2DU BalUn is an example of a current
BalUn with a 1:1 ratio. It is also a choke. Very few BalUns that are
published on the web are current BalUns. Similarly, very few have the
necessary choking action.

One solution is to feed a W2DU BalUn, that in turn feeds any BalUn
with the required transformation ratio, that then in turn feeds the
antenna. The W2DU BalUn takes care of the proper choking action
needed. However, this may not work with the internal BalUns found in
nearly every tuner on the market. (How does one insert the choke to
an internal BalUn?) Problem here is that if there is ANY path to
ground that goes around the choke, you have just made it an exercise
in futility.

And lastly, you have described a number of problems with the antenna
that were both inside and outside of the focus of gain. ALL were
functions of Common Mode currents. Choking the line is the best
all-around solution.

73's
Richard Clark, KB7QHC

Update on the 10 meter Lazy H...

I did a little reading on ladder line at the web page below;

http://www.athensarc.org/ladder.asp

and then in the ARRL handbook.

With the knowledge gained form the two sources I made the following
changes;

I changed the length of the 450 ohm ladder line feeding the antenna
to make sure it was not a multiple of a 1/2 wavelength at 10 meters,
and the antenna tuner was able to tune the Lazy H more easily. I also
suspect there may be a problem with the balun in the Dentron MT-3000a
tuner. When I hook up the Drake MN-75 tuner with the internal 4:1
balun I hand wound myself I am seeing gain from the Lazy H antenna in
it's preferred direction compared to the dipole, but when I switch to
the Dentron MT-3000a I am not seeing gain when I compare the dipole to
the Lazy H. I think I am going to remove the factory balun from the
Dentron MT-3000a and hand wind a new 4:1 balun for it.

Michael Rawls
KS4HY

Woohoo! The center fed Lazy H is now working with gain in it's most
favored directions, and it is now consistently out performing the
dipole. I had already pointed the extended double zepp in another
direction, so I'm not sure if the Lazy H is out performing the
extended double zepp.

Below are the following real world lessons I learned from building the
Lazy H wire antenna in the real world. Hopefully it will save future
builders some time.

1) Make sure the 450 ohm ladder line exiting the center of the Lazy H
back to the antenna tuner goes away from the Lazy H at a 90 degree
angle for at least a full wavelength or more or it will skew the
radiation pattern of the antenna.

2) Cut the 450 ohm ladder line going back to the tuner to a length
that is NOT a multiple of a half wavelength on the frequency (or
frequencies) you plan to use the antenna on. In my case since I only
plan to use the Lazy H on 10 meters I found the length required to get
back to the radio room, and then I added length until the total length
landed in between multiples of a 1/2 wave at the antenna design
frequency. The antenna tuner was more easily able to tune the Lazy H
once I did that. When I measured the total length of the ladder line
feeding the Lazy H I included one half of the phasing line that
connected the top and bottom elements.

3) Do not allow sag in the ladder line back to the antenna tuner where
the exiting ladder line falls close to the bottom half of the 450 ohm
phasing line that is used to connect the top and bottom of the Lazy H
or the SWR reading will go up noticeably.

4) The setting on the antenna tuner where a lowest SWR is tuned may
not be the same setting where the receiver receives the strongest
signal from the antenna. This quirk may be specific to my Dentron
MT-3000a tuner and it's internal factory balun.

5) Following number 2 above will probably avoid this situation, but if
your antenna tuner is unable to match the Lazy H at any setting change
the length of the ladder line feeding the Lazy H.

Michael Rawls
KS4HY

Dear Michael KS4HY: Thanks for the up-date. You have indicated some ways
to deal with the issues you encountered.

To emphasize what others have said: The issues you encountered would have
been attenuated with common-mode chokes being used at feed-points (and
perhaps at strategic places farther along).

73, Mac N8TT

"Michael" wrote in message
...


Woohoo! The center fed Lazy H is now working with gain in it's most
favored directions, and it is now consistently out performing the
dipole. I had already pointed the extended double zepp in another
direction, so I'm not sure if the Lazy H is out performing the
extended double zepp.

Below are the following real world lessons I learned from building the
Lazy H wire antenna in the real world. Hopefully it will save future
builders some time.

1) Make sure the 450 ohm ladder line exiting the center of the Lazy H
back to the antenna tuner goes away from the Lazy H at a 90 degree
angle for at least a full wavelength or more or it will skew the
radiation pattern of the antenna.

2) Cut the 450 ohm ladder line going back to the tuner to a length
that is NOT a multiple of a half wavelength on the frequency (or
frequencies) you plan to use the antenna on. In my case since I only
plan to use the Lazy H on 10 meters I found the length required to get
back to the radio room, and then I added length until the total length
landed in between multiples of a 1/2 wave at the antenna design
frequency. The antenna tuner was more easily able to tune the Lazy H
once I did that. When I measured the total length of the ladder line
feeding the Lazy H I included one half of the phasing line that
connected the top and bottom elements.

3) Do not allow sag in the ladder line back to the antenna tuner where
the exiting ladder line falls close to the bottom half of the 450 ohm
phasing line that is used to connect the top and bottom of the Lazy H
or the SWR reading will go up noticeably.

4) The setting on the antenna tuner where a lowest SWR is tuned may
not be the same setting where the receiver receives the strongest
signal from the antenna. This quirk may be specific to my Dentron
MT-3000a tuner and it's internal factory balun.

5) Following number 2 above will probably avoid this situation, but if
your antenna tuner is unable to match the Lazy H at any setting change
the length of the ladder line feeding the Lazy H.

Michael Rawls
KS4HY


J. C. Mc Laughlin
Michigan U.S.A.
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