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Ward - I thank you for your reply. I will review the report futher.
The major hangup that I have is with is with the position, that some have
taken, that all of the antennas one would look at would have extremely
simular/identical patterns. Having identical patterns would indeed minimize
the risks of inaccuracies in comparing unit to unit [to a dipole ] in a ground
enviroment. The problem I have , with the identical pattern position, should
survive the e-mail hurtle :
1 I thought antennas realized gain through the change of it's radiation
pattern.[ ie it reduces the power in some undesired directions and directs it
in a desired direction - vola!! GAIN. If true --- antennas with different
gains must have different patterns.
2 If antenna's have different patterns will they not be effected differently
in a "real world" ground enviroment??
3 If the same antenna [ in this case a c-3 ] is installed and tested two or
more times [ and the data repeats within 1 db ] it is reasonable to assume
that its pattern and the "world" [ignore measurement calibrations] have not
changed. Thats what you have experienced and no reasonable person would have
expected major changes. It is a major leap tho to assume a much different
antenna would measure higher or lower only due to the antennas gain and not
due to the "test fixture"reacting to a different pattern.
If you can just help me over the pattern problem I will be happy.
I agree that your testing efforts have been very positive and have contributed
to the understanding of Tri-band antenna measurements and performance. I take
my hat off to you guys for making a great effort and sharing the results. I
too hope more tests will occur [ as Roger Cox has also proposed ] and some of
the questions can be answered. I would also hope an open discussion about
those tests would occur as they have here. I think it is improper for some to
imply that it is not right to ask questions[about tests ] unless you have run
some yourself. -- the questions have nothing to do with people or products
being good or bad. 73 and thanks. Larry
Ward Silver wrote:
> > I thought the antenna measurement discussion had run it's course,
> > however, it appears Steve you have been hiding "your light under a
> > bushel" [ think that's Shakespere but not sure.]
>
> The Bible, actually...but I digress...
>
> > What are the specifics of the technical argument that would convience a
> > reasonable person that antenna pattern differences [ with differing
> > antenna designs, [sizes, configurations etc] do not exist, that all
> > "ground associated" effects will impact all antennas equally and that
> > measureing in a theorical lobe null is as reasonable [ for accuracy ] as
> > measuring at a lobe maximum ???
>
> I believe that what Steve is suggesting is that the discussion is really
> quite beyond the scope of email, in particular email to the hundreds of
> reflectorites. We present a number of arguments in favor of considering
> the protocol useful. Without your having read them, it is difficult to
> summarize in email because of its length and detail. The discussion W8JI
> and K2AV have had certainly captured the major issues and I suggest that
> you review those arguments.
>
> Permit me to add an observation that may help clarify things. What W8JI
> has identified are *risks*. He is quite right to identify risks and I
> anticipated discussions of this nature when writing the report. In the
> context of testing, a risk is the possibility that the measurement is not
> valid for the purpose intended - namely, useful comparisons of antenna
> performance. Whenever a test does not measure a parameter directly and
> with absolute traceability to standard references, risks are involved and
> must be dealt with.
>
> Our position is that the risks are manageable. Validation of a test
> protocol can be acheived in one of three ways; historical results,
> analysis of the protocol, and additional tests (i.e., developing
> historical results). We recognize that because this is a new protocol,
> there is no history and the environment renders analysis untenable. That
> is why additional testing is needed - as pointed out several times in our
> report.
>
> The results from the test, to my mind, also indicate (not confirm) that
> the test is reasonable because the gain figures vs. boom length trend
> similarly to theoretical figures from W2PV monobander designs. Also,
> repeated measurements of one antenna (the C3) were very similar (1 dB of
> variation) over time, apparently tolerant, if not independent, of ground
> conditions. These observations by themselves, of course, are not
> sufficient to validate the protocol. Only additional testing which
> generates similar results would do that. To date, there is isn't exactly
> a line around the block pushing and shoving to get their antennas up in
> the air, so the question will have to remain open for now.
>
> Trying not to sound too self-commercializing, you will simply have to read
> the report and decide for yourself whether the protocol generates risks
> that are too large to be "reasonable". All of our arguments, processes,
> and results are there and in public for your review and comment.
>
> Have at it!
>
> Thanks for your interest and 73,
> Ward N0AX
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<font size=+1>Ward - I thank you for your reply. I will review the
report futher.</font>
<br><font size=+1>The major hangup that I have is with is with the position,
that some have taken, that all of the antennas one would look at would
have extremely simular/identical patterns. Having identical patterns would
indeed minimize the risks of inaccuracies in comparing unit to unit [to
a dipole ] in a ground enviroment. The problem I have , with the identical
pattern position, should survive the e-mail hurtle :</font>
<br><font size=+1>1 I thought antennas realized gain through the
change of it's radiation pattern.[ ie it reduces the power in some undesired
directions and directs it in a desired direction - vola!! GAIN. <u>If true
---</u> antennas with different gains <u>must have different
patterns.</u></font>
<br><font size=+1><u>2 If</u> antenna's have different patterns
will they not be effected differently in a "real world" ground
enviroment??</font>
<br><font size=+1>3 If the same antenna [ in this case a c-3 ] is installed
and tested two or more times [ and the data repeats within 1 db ] it is
reasonable to assume that its pattern and the "world" [ignore measurement
calibrations] have not changed. Thats what you have experienced and no
reasonable person would have expected major changes. It is a major leap
tho to assume a much different antenna would measure higher or lower only
due to the antennas gain and not due to the "test fixture"reacting to a
different pattern.</font>
<br><font size=+1>If you can just help me over the pattern problem I will
be happy.</font><font size=+1></font>
<p><font size=+1>I agree that your testing efforts have been very positive
and have contributed to the understanding of Tri-band antenna measurements
and performance. I take my hat off to you guys for making a great effort
and sharing the results. I too hope more tests will occur [ as Roger Cox
has also proposed ] and some of the questions can be answered. I would
also hope an open discussion about those tests would occur as they have
here. I think it is improper for some to imply that it is not right to
ask questions[about tests ] unless you have run some yourself. --
the questions have nothing to do with people or products being good or
bad. 73 and thanks. Larry</font>
<br>Ward Silver wrote:
<blockquote TYPE=CITE>> I thought the antenna measurement discussion had
run it's course,
<br>> however, it appears Steve you have been hiding "your light under
a
<br>> bushel" [ think that's Shakespere but not sure.]
<p>The Bible, actually...but I digress...
<p>> What are the specifics of the technical argument that would convience
a
<br>> reasonable person that antenna pattern differences [ with differing
<br>> antenna designs, [sizes, configurations etc] do not exist, that all
<br>> "ground associated" effects will impact all antennas equally and
that
<br>> measureing in a theorical lobe null is as reasonable [ for accuracy
] as
<br>> measuring at a lobe maximum ???
<p>I believe that what Steve is suggesting is that the discussion is really
<br>quite beyond the scope of email, in particular email to the hundreds
of
<br>reflectorites. We present a number of arguments in favor of
considering
<br>the protocol useful. Without your having read them, it is difficult
to
<br>summarize in email because of its length and detail. The discussion
W8JI
<br>and K2AV have had certainly captured the major issues and I suggest
that
<br>you review those arguments.
<p>Permit me to add an observation that may help clarify things.
What W8JI
<br>has identified are *risks*. He is quite right to identify risks
and I
<br>anticipated discussions of this nature when writing the report.
In the
<br>context of testing, a risk is the possibility that the measurement
is not
<br>valid for the purpose intended - namely, useful comparisons of antenna
<br>performance. Whenever a test does not measure a parameter directly
and
<br>with absolute traceability to standard references, risks are involved
and
<br>must be dealt with.
<p>Our position is that the risks are manageable. Validation of a
test
<br>protocol can be acheived in one of three ways; historical results,
<br>analysis of the protocol, and additional tests (i.e., developing
<br>historical results). We recognize that because this is a new
protocol,
<br>there is no history and the environment renders analysis untenable.
That
<br>is why additional testing is needed - as pointed out several times
in our
<br>report.
<p>The results from the test, to my mind, also indicate (not confirm) that
<br>the test is reasonable because the gain figures vs. boom length trend
<br>similarly to theoretical figures from W2PV monobander designs.
Also,
<br>repeated measurements of one antenna (the C3) were very similar (1
dB of
<br>variation) over time, apparently tolerant, if not independent, of ground
<br>conditions. These observations by themselves, of course, are not
<br>sufficient to validate the protocol. Only additional testing
which
<br>generates similar results would do that. To date, there is isn't
exactly
<br>a line around the block pushing and shoving to get their antennas up
in
<br>the air, so the question will have to remain open for now.
<p>Trying not to sound too self-commercializing, you will simply have to
read
<br>the report and decide for yourself whether the protocol generates risks
<br>that are too large to be "reasonable". All of our arguments,
processes,
<br>and results are there and in public for your review and comment.
<p>Have at it!
<p>Thanks for your interest and 73,
<br>Ward N0AX</blockquote>
</html>
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