[Antennas] DCTL Antenna Question

Sat, 28 Feb 2004 07:11:49 +0000

Dear Bob,
If the Antenna is resonant and constructed of 450 ohm line, then it should 
have a load impedance of 450 ohms, right? I am feeding it with 450 ohm line 
and then using a 9:1 balun to my 50 ohm transmitter. Or at least that is 
what I want to do.  The original design at http://www.n5nw.org/antennas.html 
is done with 300 ohm twinlead and a 6:1 "balun" I want to avoid the rather 
awkward 6:1 match in the one I build, particularly since I dont want to use 
a tuner.

450 ladder and 300 twinlead have very different Capacitance and velocity 
factors, so I need to compensate in the construction. My question is HOW.

Thanks for the response.

  "Communications" is a People skill, the rest is technology.
             Durwydd MacTara

>From: "Robert Lay" <[email protected]>
>To: "Durwydd MacTara" <[email protected]>
>Subject: Re: [Antennas] DCTL Antenna Question
>Date: Sat, 28 Feb 2004 01:15:44 -0500
>
>Dear Durwydd,
>
>You are placing entirely too much significance on the characteristic
>impedance of the transmission line. As a consequence you are worrying about
>matching a characteristic impedance to the 50 ohm transmitter.
>
>You are supposed to be matching the actual load to the 50 ohm transmitter -
>isn't that right?
>
>Bob Lay (W9DMK), Dahlgren, VA
>[email protected]
>http://www.qsl.net/w9dmk
>

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