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Old April 24th 09, 10:52 PM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default Coax Collinear Element Materials and Velocity Factor

"Antonio Vernucci" wrote in
:

Ok, firstly, there was a mistake in my formula... it is missing a
pair of parentheses, and should be (1-10^(-(3.941e-6*f^0.5)/10))*100.

That correctly finds 1.08%/m for R loss.

From my spreadsheet check, =(1-10^(-(0.00000000001031*f)/10))*100
correctly calculates 0.034%/m. Note the exponent of f is 1 in the G
case.

Apologies for the parenthesis omission. I wrote down what I 'did' on
an RPN calculator rather than copying an expression that evaluated
properly.

Does this answer your question?


Owen,

I simply pasted and copied your formulas in my Excel.

For f=144:

- the first formula gives me 0.00108893 that is 0.108%, which is 10
times lower than your figure
- the second formula gives me 3.41851e-08 that is 0.0000034%, which is
10,000 times lower than your figure

I did that three times, same results.....

I cannot understand what can be wrong....

Tony I0JX



Ok, you have calculated for 144Hz. Try f=144e6 and don't format the cells
with %.

Owen