Thread: NVIS and VHF?
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Old May 26th 11, 02:50 AM posted to rec.radio.amateur.antenna
tom tom is offline
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First recorded activity by RadioBanter: May 2009
Posts: 660
Default NVIS and VHF?

On 5/25/2011 8:44 PM, tom wrote:
On 5/24/2011 8:08 PM, Ralph Mowery wrote:
"John wrote in message
...

75 feet, at 144 MHz
LMR240 - 2.2 dB
Belden 8215 (RG-6A) - 2.5 dB
Belden 9258 (RG-8x) - 3.0 dB
Tandy RG-8x - 3.1 dB
Belden 8267 (RG-213) - 1.9 dB
Wireman CQ110 (RG-213) - 1.6 dB
Belden 8237 (RG-8) - 1.7 dB
belden 8213 (RG-11) = 1.2dB


Huh? 75 ft of RG-11 has almost 8dB of loss at 146MHz. 75 ft of LMR240
has
9.7dB of loss at 146 MHz.

I won't go through your entire list.

Check out http://www.vk1od.net/calc/tl/tllc.php

Cheers,
John


John you need to see where you went wrong. The numbers Jim listed are
either correct or very close. I did not bother to do the calculations,
but
looking at a 100 foot chart, the numbers are very close and no where near
the numbers you have.

I thought you may have looked at the web page and missed it defauls to
meters, but that does not seem to be the case to me.



According to the loss calculator at Times Microwave the loss at 144 MHz
for a 75 length of LMR 240 is 2.952. 100 METERS is 9.687.

Perhaps you misread.

tom
K0TAR


Oops, needed to do this one level up. Should have responded to John.

tom
K0TAR