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Old April 23rd 09, 09:55 PM posted to rec.radio.amateur.antenna
Antonio Vernucci Antonio Vernucci is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 395
Default Coax Collinear Element Materials and Velocity Factor

Hi Owen

I would like to put a question regarding a previous discussion.

Not having your e-mail address, I have to catch you on another thread.

I report below what you wrote at that time:

QUOTE
From TLLC, the matched line loss in dB of LMR400 (a foam coax of similar OD to
RG213) is
3.941e-6*f^0.5
+1.031e-11*f
The first term is due to R and the second due to G.

At 144MHz, the percentage of power lost per meter due to R is
(1-10^-(3.941e-6*f^0.5)/10)*100 is 1.08%. If you do similar for G, the loss is
0.034%, so loss in R is more than 30 times loss in G
UNQUOTE

I put those formulas on a spreadsheet, but I only obtain the 0.034% figure if I
change the second formula into +1.031e-5*f (instead of +1.031e-11*f)

Any comment?

Thanks and 73

Tony I0JX
Rome-Italy