Sommer design
 

The Sommer design is stated as having "phasing line similar to log
periodic array". Am I correct in thinking that it is not a true LPA
because of different element sizing and spacing than an LPA?

If so, what is the advantage of the "LPA-like" phasing line in this case?

John
AB8O

Sommer design
 

I Googled SommerAntennas so I could get a look at what you are writing about and
got a 'Could not be found' message for http://www.sommerantennas.com/.

In either case a LP design has many solutions for a given frequency range for
number of elements, spacing, etc. A true LPDA will operate anywhere within it's
minimum and maximum frequency range. That is: a 13.5 to 33 MHz design will
operate ANYWHERE within that range and meet published specifications for Gain,
VSWR, efficiency, without the need for ANY on tower tuning, etc. [An LP does NOT
have the 20, 17, 15, 12 and 10 meter bands!!! It has FULL coverage ANYWHERE
within it's published minimum and maximum frequencies.]

A LP design is a driven array NOT a parasitic [YAGI} design. It's major
advantage is the very broad bandwidth it covers without tuning, traps, or stubs.
It provides slightly less 'gain' than a 3 element triband Yagi. A Long John
single band YAGI will have 3 to 6 dB additional gain above a LP, but the YAGI is
band limited.

- - -



jawod wrote:

The Sommer design is stated as having "phasing line similar to log
periodic array". Am I correct in thinking that it is not a true LPA
because of different element sizing and spacing than an LPA?

If so, what is the advantage of the "LPA-like" phasing line in this case?

John
AB8O

Sommer design
 

On Mon, 21 Aug 2006 16:37:09 -0400, jawod wrote:

If so, what is the advantage of the "LPA-like" phasing line in this case?

Hi John,

Yes, it is an interesting coupling mechanism. It is something of a
delta match going from element to element with a phase reversal (to
boost the number of degrees that would otherwise force a greater
distance into the boom).

73's
Richard Clark, KB7QHC

Sommer design
 

Dave wrote:
I Googled SommerAntennas so I could get a look at what you are writing
about and got a 'Could not be found' message for
http://www.sommerantennas.com/.

In either case a LP design has many solutions for a given frequency
range for number of elements, spacing, etc. A true LPDA will operate
anywhere within it's minimum and maximum frequency range. That is: a
13.5 to 33 MHz design will operate ANYWHERE within that range and meet
published specifications for Gain, VSWR, efficiency, without the need
for ANY on tower tuning, etc. [An LP does NOT have the 20, 17, 15, 12
and 10 meter bands!!! It has FULL coverage ANYWHERE within it's
published minimum and maximum frequencies.]

A LP design is a driven array NOT a parasitic [YAGI} design. It's major
advantage is the very broad bandwidth it covers without tuning, traps,
or stubs. It provides slightly less 'gain' than a 3 element triband
Yagi. A Long John single band YAGI will have 3 to 6 dB additional gain
above a LP, but the YAGI is band limited.

- - -



jawod wrote:

The Sommer design is stated as having "phasing line similar to log
periodic array". Am I correct in thinking that it is not a true LPA
because of different element sizing and spacing than an LPA?

If so, what is the advantage of the "LPA-like" phasing line in this case?

John
AB8O



Dave,John

Just tried the WEB site and I had to hit the try again button to get the
response, I spoke with Alf the Owner last Friday and advised him of the
site trouble, he said that the server was giving them fits. The Sommer
factory located in Geneva FL was going at fill steam to meet the Govt
(Military demands) from around the world. Several Govt have
standardized on the Sommer antenna. Its not that Ham Radio has taken a
back seat but you go where the money is!

Alf invited me to come to the factory, see the antennas up in the air
and see what they have to offer. Alf claims that his XP504 LP has the
same gain as a 4-element Yagi on the ham bands. He has the review facts
from a French Government study. The only problem I can see with this
antenna is the weight (73#'s) compared to a lower weight of 43#'s form
SteppIR and from other antennas. I was hoping to get access to the
QTH.net archives but they have disappeared. Was looking to read what
others had to say. Anyone know how to get archives or where they are?

The SteppIR caught my attention a few years back and I was considering
one of those antennas as a replacement for my current TA-33 trap style
tribander which has performed very well but lacks the WARC bands plus
the six meter band if I want. For 30 and 40 meters there is a kit for
the Sommer but from what I have read your better off with a dipole for
the added costs. Several articles I have read seem to backup what Alf
had to say plus reports from on the air comparisons. From what I hear
it is built like a tank with quality products.

Give the site another try and keep hitting the refresh button and it
will finally respond. After my visit which I hope happens this coming
Saturday I give you and the rest a report.

Ron - W4LDE

Sommer design
 

Ron Walters wrote:
Dave wrote:

I Googled SommerAntennas so I could get a look at what you are writing
about and got a 'Could not be found' message for
http://www.sommerantennas.com/.

In either case a LP design has many solutions for a given frequency
range for number of elements, spacing, etc. A true LPDA will operate
anywhere within it's minimum and maximum frequency range. That is: a
13.5 to 33 MHz design will operate ANYWHERE within that range and meet
published specifications for Gain, VSWR, efficiency, without the need
for ANY on tower tuning, etc. [An LP does NOT have the 20, 17, 15, 12
and 10 meter bands!!! It has FULL coverage ANYWHERE within it's
published minimum and maximum frequencies.]

A LP design is a driven array NOT a parasitic [YAGI} design. It's
major advantage is the very broad bandwidth it covers without tuning,
traps, or stubs. It provides slightly less 'gain' than a 3 element
triband Yagi. A Long John single band YAGI will have 3 to 6 dB
additional gain above a LP, but the YAGI is band limited.



Dave,John

Just tried the WEB site and I had to hit the try again button to get the
response, I spoke with Alf the Owner last Friday and advised him of the
site trouble, he said that the server was giving them fits. The Sommer
factory located in Geneva FL was going at fill steam to meet the Govt
(Military demands) from around the world. Several Govt have
standardized on the Sommer antenna. Its not that Ham Radio has taken a
back seat but you go where the money is!

Alf invited me to come to the factory, see the antennas up in the air
and see what they have to offer. Alf claims that his XP504 LP has the
same gain as a 4-element Yagi on the ham bands. He has the review facts
from a French Government study. The only problem I can see with this
antenna is the weight (73#'s) compared to a lower weight of 43#'s form
SteppIR and from other antennas. I was hoping to get access to the
QTH.net archives but they have disappeared. Was looking to read what
others had to say. Anyone know how to get archives or where they are?

The SteppIR caught my attention a few years back and I was considering
one of those antennas as a replacement for my current TA-33 trap style
tribander which has performed very well but lacks the WARC bands plus
the six meter band if I want. For 30 and 40 meters there is a kit for
the Sommer but from what I have read your better off with a dipole for
the added costs. Several articles I have read seem to backup what Alf
had to say plus reports from on the air comparisons. From what I hear
it is built like a tank with quality products.

Give the site another try and keep hitting the refresh button and it
will finally respond. After my visit which I hope happens this coming
Saturday I give you and the rest a report.

Ron - W4LDE
Thanks, Ron.

Yes, the website is up and down. If you can get on it, it's a fairly
informative site. I didn't realize there was such a weight diff. I'm
actually dreaming of my first tower several years away. Who knows, by
then, a large nerfball sphere may digitally reproduce any propagation
you wish...or at least that's one of my other dreams.

Is Alf referring to the XP504 as a log periodic dipole array? I have no
intention of being a stickler...just curious. In the ARRL antenna book,
there are several formulas to follow in order to design an LPDA and the
XP504 doesn't look like it would conform. There is also a hybrid
LP-Yagi, using a director parasitic element, listed there.

In my mind, the weight difference alone leans heavily (horrible pun)
toward the SteppIR. Man, the Sommer is almost TWICE as heavy.

John
AB8O

PS, Is this Alf fuzzy and short? I may know him.

Sommer design
 

Man, the Sommer is almost TWICE as heavy.

And the Sommer has lebenty zillion clamped, screwed, and riveted, RF
connections which will not take kindly to oxidation, salt air, etc...

denny

Sommer design
 

The Sommer design takes advantage of different elements phased to operate on
all of the bands from 20 to 10. The longest element can be adjusted to
operate on either 30 or 40.

One one band all the elements might operate as half wave elements but on
another they would operate as 3/4 wave elements or even ful wave elements.

If properly assembled and adjusted (and that is not easy) the Sommer beam
can be quite effective for the given boom length.

There was an execellent article in Dx magazine about how KM1E slected the
Sommer XP708 over other antennas in late 1995.

Dave K4JRB