SV: [antennaware] Antenna for 80M!

[Eric Gustafson]

Hi Mike,

You can match a delta loop directly to 50 ohms by operating it a
bit "squashed".  Doing this has a number of benefits.  You get a
bit more gain (the veritcal radiators are a bit farther apart),
it has a feedpoint resistance of 50 ohms at resonance, and it
requires a shorter vertical support, and the feedpoint moves down
from part way up the side into the exact bottom corner of the
loop.

Put the apex at about 50 feet.  Establish the height of the base
wire as 12 feet.  Make the horizontal wire long enough to bring
the structure into resonance at the desired frequency.  An RF
choke of some sort is required on the coax at the feedpoint.
Ferrite Bead stack baluns work well for this.  But the balun is
necessary for any delta loop configuration.  Feeding in the
corner is very convenient.

73, Eric  N7CL


>From: "Mikael Larsmark" <larsmark@swipnet.se>
>Date: Sat, 10 Apr 1999 17:55:28 +0200
>
>Hi again!
>
>When making a vertical deltaloop i should have 1/4 75ohm coax
>before connectening it to the 50ohm cabel, is that right?
>
>Thanks for the tips!
>73 de sm3wmv / Mike!

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