Parallel coax
"kg7fu" wrote in message
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On 09/27/2015 11:22 AM, John S wrote:
On 9/27/2015 9:41 AM, kg7fu wrote:
Doubling the number of feedlines would double the losses. Not only that
but each connector in the system inserts losses so that number
would be 4x.
How can that be? Each line carries half the power.
Connector loss at 14MHz is insignificant.
Connector losses are static up to UHF at around .5db per connector for a
typical PL-259/SO-239 pair. Insertion losses for professional grade
connectors on high quality rigid and semi-rigid coax such as Andrew Heliax
are around .05db.
Where did you get the .5 db loss per connector ?
If you would think for about 1 minuit,you would see that has to be wrong.
To make things simple and using round numbers. Take 2 PL-259 connectors and
a barrel connector and put them together. Not counting the barrel that
would be 1 db of loss. That is about 25 %. Using a 100 watt transmitter,
that is 25 watts of heat in a couple of inches. It would get warm. Bumping
it up to the 1 KW level that lots of hams use, that is 250 watts. It would
melt down in a short order.
The loss is around .01 db per connector around 100 MHz, about half that at
10 MHz.
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