Topband: Dipole/remote tuner

[Jim Brown]

On 11/14/2022 11:41 PM, Roy Morgan wrote:
> Do not spend money on a remote antenna tuner till you understand transmission line truth.

Yes, there is much that is misunderstood about transmission lines by 
those who have chosen not to learn the fundamentals. The ARRL Handbook 
is a great place to start.

Unless the transmission line for a 160M antenna is VERY long, it makes 
little sense to go to the trouble of weatherproofing a dedicated 
autotuner at the antenna, even if the antenna is a terrible match to the 
line. That's because loss in any decent RG8 is quite low at 2 MHz, and 
even with a fairly long line, bigger coax is probably a lower cost and 
much simpler solution.

If you know the complex feedpoint impedance, there are many computer 
programs and apps that can compute the loss in nearly all popular 
feedline type. Many analyzers can measure it and output it as a data 
file for use in those programs. The CD that comes with the ARRL Antenna 
Book includes N6BV's TLW, which can make that calculation for the data 
at any single frequency.

73, Jim K9YC