[Elecraft] K3 - Numeric SWR Display

[Ron D'Eau Claire]

That's true. Indeed, if you have an "antenna tuner" (built-in automatic or
external manual) you don't even need to do that. That's what made them so
popular in recent years; they "fix" impedance problems at the rig end
without fiddling around with the antenna at all. 

The issue then becomes feed line loss. It can get quite high, especially at
the higher frequencies and with longer lengths of coax. It's not unusual to
throw away 50%, 75% or more of your RF as heat along a coaxial line that
way. 

But, if your antenna is designed to provide a decent match, or if you've
done some adjustments 'on the ground' that suggest you're at least
approximately correct, you're not likely to experience such drastic losses
even though things will change when the antenna is raised to its final
position.

Doing measurements up on a tower is one of the major reasons for the
popularity of the modern "antenna analyzers". They're self contained and
small enough you can carry one up to the feed point. Most Hams only need to
do that at rare intervals, which is why many Ham clubs have a "club
analyzer" everyone's contributed to buying so members can borrow it on
occasion. 

A much cheaper approach is, as Bill says, to cut some coax to a multiple of
1/2 wave, electrically. Then the impedance you see at the end on the ground
will be the impedance at the antenna. The issue there is "how many times do
you want to climb the tower"? Perhaps a buddy at the rig on the ground and
you in the air with some HT's is the answer to that.

Ron AC7AC

-----Original Message-----



Since I don't plan on hanging off the side of the tower to operate my
station, isn't it more prudent to tune the entire "system", flaws, feedline
and all if my main concern is what SWR my equipment, in my shack, sees?

Charlie
KI5XP