[Antennaware] Help with Short Dipole

[N4ZR]

And this is what the antennaware reflector is for. Great discussion, guys!

73, Pete N4ZR
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On 3/5/2019 8:26 PM, Guy Olinger K2AV wrote:
> At this point in the experiment, you wind it, put it on the analyzer, read
> it, use it. It will show the separate R and X.  Measure, measure, measure
> and type the facts into the EZNEC loads. The more stuff in the model is
> hard fact, the more accurate the model is going to be. Those values of
> inductive reactance make for really big coils, like really big.
>
> Be sure and come back with your results.
>
> 73, Guy
>
>
>
> On Tue, Mar 5, 2019 at 6:35 PM Gedas <w8bya at mchsi.com> wrote:
>
>> Hi Guy. ok now that I have an initial model built correctly I can
>> proceed with my experimentation. You had asked "The next question, what
>> are you trying to accomplish with this? You wanting to put this in the
>> air? Coming up with the coils will be interesting. 1265 ohms X is a lot
>> of wire turns." The simple answer is pure fun mixed with a little science.
>>
>> In reality I have the property to make a full sized inv-v type dipole
>> for this frequency and suspend it from 85' but I realize even this would
>> be a pure cloud warmer as the antenna is kissing the ground. Your
>> analogy of the 40m antenna is spot on. But I could eliminate the
>> inductors completely if I wanted to. I am doing this out of curiosity. I
>> like to see how reality differs from different models using different
>> models.
>>
>> Ok, so getting back to this antenna.....I already have the 160m dipole
>> up in the air operating and it is purely curiosity driving me to try
>> this antenna. I know with 100% certainty that I will be going with a
>> vertical radiator fed against some sort of ground but given I like to
>> play with antennas, in particular model them, build them, and actually
>> put them on the air this is only for my personal gratification and my
>> own curiosity.
>>
>> I should note that the values of "R" for the inductors in my model were
>> 100% guesses on my part before I did any calculations. That was going to
>> be my next question to you. I was wondering if a half-way accurate
>> number for the resistive component could be obtained before the
>> inductors built and measured. I do own a VNA (actually an ENA) from
>> Agilent that may help me get an accurate number but I am wondering how
>> accurate the number would be based on the predicted Q from some of the
>> better Inductor Calculator programs out there.
>>
>> I have just run several calculations to make a large inductor using a
>> 4.5" dia form and if one can trust the predicted Q at this frequency to
>> be around 400 is it safe to initially use a value of 3.2 ohms for R?
>>
>> I will of course measure it with the VNA to see how close this number is
>> but is this the value for R that I would use (R derived from XL/Q) ?
>>
>> Gedas, W8BYA
>>
>> Gallery at http://w8bya.com
>> Light travels faster than sound....
>> This is why some people appear bright until you hear them speak.
>>
>>
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