[Antennas] Loading a 90 foot wire on 160

[Rob Matherly]

Thanks for the info!  I figured my tuner woulda been able to handle it, but it didn't
:^)  I went out and threw 22 feet of wire onto the end of it just for the heck of it,
that raised the SWR on 80, haven't tried on 160 yet.  Will look through my handbook
later to see what changes I need to make to your numbers for the longer radiator.
(Plus I forgot about the approx. 7 feet going from the wire to my tuner... duh :^))

72/73/oo
Rob, W�JRM
ARRL; FP QRP -330; IA QRP #143; SOC #497; QRPp-I #19; Live-Wire #442;

Visit my website! http://www.qsl.net/w0jrm

"Those who control their tongue will have a long life;
     a quick retort can ruin everything"   -- Proverbs 13:3 NLT

----- Original Message -----
From: Dave Shrader <dshrader@earthlink.net>
To: <kc0bom@arrl.net>
Cc: <antennas@mailman.qth.net>
Sent: Tuesday, May 21, 2002 7:03 PM
Subject: Re: [Antennas] Loading a 90 foot wire on 160


ARRL Antenna Handbook, Chapter 6, 18th Edition.

You need about 28 uH to 'base' load your 90 foot antenna at 1.8 MHz.
That is a coil about 6 inches long, 6 turns per inch and 2 1/2 inches
diameter; or, 3 1/2 inches long, 8 turns per inch, 2 1/2 inches
diameter.

This will resonate your antenna. At 90 feet, feed point or base loaded,
on 160 meters the radiation resistance is about 15 to 17 ohms [VSWR of 3
to 1 in a 50 ohm coax system].

If your coil meets or is close to these dimensions then the answer is to
tap the coil at about 20% up from the ground [cold] end. Adjust tap for
best VSWR.

Remember to use a good counterpoise or radial system as appropriate.

73, Deacon Dave, W1MCE
Manager, Textron Antenna Range, retired.

Rob Matherly wrote:
>
> Like the subject says, I'm trying to load a 90 foot wire on 160.