How do you match it? I assume it is a full wave length (length = 1005/MHz)
loop. A Delta Loop requires a matching network and in some cases the
matching network is frequency dependent, e.g. a quarter-wave 75 ohm matching
or "Q" line. With a nominal impedance of 100 ohms at the frequency for
which it was designed, For multi-band use (higher frequencies to the design
frequency), one can use a 4:1 balun along with a half-wave length of 450 ohm
ladder line and a transmatch. The definitive article (W1FB) along with
results stating that it works great at higher frequencies (with the correct
matching system) is in QST September 1985. It is the reference most likely
copied ever since that date and I am pretty sure you'll find it any ARRL
Antenna Book. If done correctly, an 80 meter delta loop is outstanding on
40 Meters and above with its low angle of radiation. Ken K5RG
Message: 10
Date: Thu, 11 Oct 2012 08:06:19 -0500
From: rfman45 <rfman45@hotmail.com>
To: <towertalk@contesting.com>
Subject: [TowerTalk] 80 meter Delta Loop on 40
Message-ID: <SNT137-W10EFCC318B4A1BAB759A5BB88D0@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
I have an 80m Delta Loop fed at a corner with the apex at about 65ft that
works really well; I consistently get great signal reports with it .
However, I have tried using it on 40 and in A/B comparisons with other
rather simple antennas its performance is dismal despite reading that it
should work OK. I'd like to hear from others on TT who have used 80m Deltas
on other bands to see what I'm doing wrong. Maybe they really don't work
well on lower bands. Thanks in advance for any suggestions.
Mike W2LO
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