Antenna experiment on UCR411

To the Group:
Here's some more antenna tests. The walks were a little different but
the antenna angles were consistent. Rodney Wildhagen in Production
Test did the walks. The original tests are at the bottom and then the
newer and the newest at the top. When there were differences, the two
vertical antennas were the best. The V setup +/- 45 degrees was still
somewhat the worst and the L pattern, one horizontal and one vertical,
close to the two vertical antennas in performance. Rodney did not
notice as much of a difference in the different setups as we did in
the first tests.
Best Regards,
Larry Fisher
Lectrosonics



Last test outdoors:
"Larry,

"We performed the outdoor range testing with the UCR411A antennas
straight up, also at +/- 45 deg, and with one vertical and one
horizontal. The result was best with both antennas straight up and
worst with one up and one horizontal.The +/- 45 deg setup (V) was in
between.

"It is noteworthy that the difference was observed with no human body
obstruction between TX and RX. With the body as an obstruction the
range performance was about the same in all three cases.

-Rodney"

Middle test indoors:
"Larry,

"As you asked, I tested a UCR411A with both antenna's straight up vs.
one up, one horizontal, and then again at +/- 45 deg (V). I found the
results to be approximately equal (same number of noise-ups in four
walks) in all three cases.

"Tests were conducted with the transmitter vertically polarized whip
antenna about chest height at the north end of the plant. I walked the
receiver east to west and back again through the stockroom along the
south wall between the entry door and the west side counting the
noise-ups. In all cases I counted between 20 and 22 in each half cycle
of walking.

"I noticed that when I had the receiver antennas at +/-45 deg (V), I
experienced noise ups when returning to my desk (near Wes' office
about 60 feet away) but did not when at least one antenna was
vertical. I interpret this to indicate that with at least one receiver
antenna polarized the same as the transmitter antenna, reception was
superior to the +/-45 degree (V) case.

"I'm keeping the gear at my desk for a bit in case you would like to
prescribe anything further.

-Rodney"




Here below is the original tests:


On Fri, 15 Feb 2008 09:33:29 -0700, Larry Fisher
<lectrosonics.RemoveThis@gmail.com> wrote:

>To the Group:
>Off and on it has been proposed to put the close mounted antennas on a
>compact receiver at angles to the receiver to add some additional
>diversity to the system. The idea was that the receiver antennas on a
>small unit are too close together and that bending them 45 degrees
>left and right would add some polarization diversity. We tried the
>experiment both indoors and out with the idea that reflections indoors
>would give us random polarization and the idea would work well; lack
>of reflections out doors might not give us the improvement since the
>signal from the body pack would be primarily vertical.
>
>The criteria was the number of dropouts as the "talent" walked a
>defined course three times each with the antennas vertical and then
>angled. We did this indoors and out. Indoors was in our plant and
>included a lot of through the walls transmission. Outdoors was line of
>sight and required some pretty long walks. The talents body blocked
>the antenna going out but did not coming back.
>
>After all 12 walks were done, the results were very consistent. The
>angled antennas were always worse! We had picked clear frequencies but
>we changed them anyway and tried it again since this was not expected.
>Same results. Vertical parallel antennas win out solidly against the
>V arrangement. Unexpected but there it is.
>Best Regards,
>Larry Fisher
>Lectrosonics

So in the REAL world of people leaning, bending and moving about, our best
weapon is still elevation and separation I presume? And for what it's
worth, my worst case normal RF reception problems usually occur with the
transmitter on someone's ankle. Would a near the floor placement like this
minimize reflection angles and make things worse?

"Larry Fisher" <lectrosonics.RemoveThis@gmail.com> wrote in message
news:nvp5s31ojp3kij5kp8u57tvevvrtggtna8@4ax.com...
> To the Group:
> Here's some more antenna tests. The walks were a little different but
> the antenna angles were consistent. Rodney Wildhagen in Production
> Test did the walks. The original tests are at the bottom and then the
> newer and the newest at the top. When there were differences, the two
> vertical antennas were the best. The V setup +/- 45 degrees was still
> somewhat the worst and the L pattern, one horizontal and one vertical,
> close to the two vertical antennas in performance. Rodney did not
> notice as much of a difference in the different setups as we did in
> the first tests.
> Best Regards,
> Larry Fisher
> Lectrosonics
>
>
>
> Last test outdoors:
> "Larry,
>
> "We performed the outdoor range testing with the UCR411A antennas
> straight up, also at +/- 45 deg, and with one vertical and one
> horizontal. The result was best with both antennas straight up and
> worst with one up and one horizontal.The +/- 45 deg setup (V) was in
> between.
>
> "It is noteworthy that the difference was observed with no human body
> obstruction between TX and RX. With the body as an obstruction the
> range performance was about the same in all three cases.
>
> -Rodney"
>
> Middle test indoors:
> "Larry,
>
> "As you asked, I tested a UCR411A with both antenna's straight up vs.
> one up, one horizontal, and then again at +/- 45 deg (V). I found the
> results to be approximately equal (same number of noise-ups in four
> walks) in all three cases.
>
> "Tests were conducted with the transmitter vertically polarized whip
> antenna about chest height at the north end of the plant. I walked the
> receiver east to west and back again through the stockroom along the
> south wall between the entry door and the west side counting the
> noise-ups. In all cases I counted between 20 and 22 in each half cycle
> of walking.
>
> "I noticed that when I had the receiver antennas at +/-45 deg (V), I
> experienced noise ups when returning to my desk (near Wes' office
> about 60 feet away) but did not when at least one antenna was
> vertical. I interpret this to indicate that with at least one receiver
> antenna polarized the same as the transmitter antenna, reception was
> superior to the +/-45 degree (V) case.
>
> "I'm keeping the gear at my desk for a bit in case you would like to
> prescribe anything further.
>
> -Rodney"
>
>
>
>
> Here below is the original tests:
>
>
> On Fri, 15 Feb 2008 09:33:29 -0700, Larry Fisher
> <lectrosonics.RemoveThis@gmail.com> wrote:
>
>>To the Group:
>>Off and on it has been proposed to put the close mounted antennas on a
>>compact receiver at angles to the receiver to add some additional
>>diversity to the system. The idea was that the receiver antennas on a
>>small unit are too close together and that bending them 45 degrees
>>left and right would add some polarization diversity. We tried the
>>experiment both indoors and out with the idea that reflections indoors
>>would give us random polarization and the idea would work well; lack
>>of reflections out doors might not give us the improvement since the
>>signal from the body pack would be primarily vertical.
>>
>>The criteria was the number of dropouts as the "talent" walked a
>>defined course three times each with the antennas vertical and then
>>angled. We did this indoors and out. Indoors was in our plant and
>>included a lot of through the walls transmission. Outdoors was line of
>>sight and required some pretty long walks. The talents body blocked
>>the antenna going out but did not coming back.
>>
>>After all 12 walks were done, the results were very consistent. The
>>angled antennas were always worse! We had picked clear frequencies but
>>we changed them anyway and tried it again since this was not expected.
>>Same results. Vertical parallel antennas win out solidly against the
>>V arrangement. Unexpected but there it is.
>>Best Regards,
>>Larry Fisher
>>Lectrosonics