[TowerTalk] Introduction

[Jim Brown]

Hi Paul,

Sounds like a wonderful QTH. Good that you've learned about HFTA. Also 
read my applications notes about antennas, especially those talking 
about horizontal vs vertical and height of both, and the one about 
160M.   The modeling that produced these notes was based on "flatland," 
and HFTA modeling should dominate your thinking when it's not flatland.  
But the lower you go in frequency, the greater the benefit of greater 
height.  k9yc.com/publish.htm

1 dB max is a good rule of thumb about feedline loss. My 120 ft tower is 
250 ft from my shack. The antennas on it are fed with 7/8-in hard line, 
all of it used, that I've scrounged from various sources. To get HFTA, 
you'll need to buy the ARRL Antenna Book. That's good -- it's an 
excellent reference, and the CD also includes N6BV's TLW program, which 
lets you calculate loss for most available feedline types for any length 
and any frequency.

By the time you do everything necessary to build it safely -- 
foundation, rated hardware, the tower itself -- low loss feedline is a 
fairly small part of the total cost. Also -- feedline loss increases 
with frequency. My 160M antennas are also about 230 ft from the shack, 
but I'm feeding them with a low loss RG8, and the loss is still only 
about 0.5 dB.

73, Jim K9YC

On Fri,2/3/2017 9:11 AM, Paul Beckmann wrote:
> Question set 1: Considering coax losses/expense how do you balance them
> against tower distance from the shack? What distance is "typical" and what
> distance is generally considered "unreasonable" from shack to tower?