On 1/17/12 9:25 AM, Steve Hunt wrote:
> Here are some "complete system" numbers drawn from EZNEC, VK1OD's line
> loss calculator, and W9CF's tuner simulator:
>
> Half-wave 80m dipole at 30ft made from #14 wire:
> Antenna copper losses: 0.19dB
> 100ft RG213 losses (matched): 0.35dB
> Tuner losses: zero - no tuner needed
> Total loss: 0.54dB
>
> 100ft dipole at 30ft made from #14 wire:
> Antenna copper losses: 0.24dB [radiation resistance is lower, so more
> current for same power; but compensated by antenna being shorter and
> therefore total RF resistance less]
> 100ft Wireman554 ladderline losses (24-j490 load): 1.75dB
> Tuner losses (1139+j3215 load): 0.2dB
> Total loss: 2.19dB
>
> Difference: 1.65dB !!!
>
Now put that matching network at the feedpoint and see what losses you
get.
What feedpoint Z did you get from EZNEC?... over what kind of soil?
(because 30 feet is pretty low for 3.5MHz)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|