[Antennas] RE: Loading a 90 foot wire on 160M w/added inductance

2002年5月22日 10:34:53 -0500

On 2002年5月22日 10:07:24 -0500, Karl Kanalz wrote:
>I agree with Jim (see his message below), but inductance added=
 at
>the *back* of the tuner, in series with the end-fed wire, will=
 pro-
>duce r.f. radiated *in* the shack. To reduce the chance of=
 that
>happening, you should put the added inductance (which appears to=
 be
>nothing more than a "loading coil") *outside* the shack in the
>feeder wire which feeds your 90-foot wire. Same effect:
>>It makes the antenna "look longer".

I've been following this thread with some interest. Most of my 
antenna construction has been building various wire antennas or=
 using 
published plans and essentially "following the instructions."
How do you determine the amount of inductance needed to=
 electrically 
shorten a wire antenna? For example, if I know that ideally I=
 needed 
a 50 foot wire but I only have 40 feet of space how do I=
 calculate 
the size of the inductor I need?
I haven't done a lot of research on this yet but my first pass 
through the current handbook hasn't provided the information so=
 far.
Tim N9PUZ