We put up a delta loop supported by balloons/kites at K8MK for the 160 contest a
couple times. It was a killer antenna.... it was sure big !!!!! Only problem
is we
always had a hard time keeping it up because the balloon/kite would brake off
and fly
away......
=========================================================
Jeffrey D. Clarke 770-218-0278 email : ku8e@bellsouth.net
Please see my resume webpage at http://home.bellsouth.net/p/PWP-ku8e
=========================================================
----- Original Message -----
From: "K4SB" <hamcat@directvinternet.com>
To: "Jeff Clarke" <ku8e@bellsouth.net>
Sent: Sunday, December 01, 2002 3:35 PM
Subject: Re: [SECC] Feeding 160 Meter Antenna
> > You said you are base loading your 160 meter inverted L that was 190 feet
> > long.
If
> > it was greater than 1/4 wl wouldn't you want to have a capacitor (not a
> > coil) to
tune
> > the antenna ??? Maybe I am missing something since I'm not an expert on
> > this....
> >
> > Jeff
>
> Don't know if this is in response to my post, but I thought I had
> clearly stated that a capacitive reactance would be required.
>
> Incidentaly, the extra length is used to raise the base impedence of
> the antenna, then tuning out the inductive reactance introduced by
> such is a simple matter of adding an equal amount of capacitive
> reactance. They cancel each other ( and yes, there is some very small
> loss ) and all the transmitter sees is the 49.7 ohms.
>
> Just the opposite theory of adding a coil if the antenna is too short.
>
> And just for the heck of it, for you guys who have 100++ ( actually
> 114') towers, you will find a full wave triangle is a real killer.
>
> 73
> Ed
>
|