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Frequency in MHz:

27.500 MHz

Length of full-wave loop:
36 feet, 6.5 inches
11.14 meters

The calculated length is approximate. In practice it's best to make the antenna a little longer than the calculated value and then trim it to get the best SWR value.

Feedpoint impedance and coaxial matching section
The feedpoint impedance at the design frequency is about 100 ohms, so full wave loops are often fed with an impedance-matching section made from a piece of 75-ohm coxial cable one quarter wavelength long (shortened to compensate for the velocity factor of the cable).

Length of an impedance-matching section with 75-ohm cable with a velocity factor of 0.66 (polyethylene dielectric):
5 feet 10.8 inches
1.80 meters
Length of an impedance matching section made with 75-ohm cable with a cable velocity factor of 0.80 (foam dielectric):
7 feet 1.9 inches
2.18 meters
http://www.66pacific.com/calculators/full-wave-loop-antenna-calculator.aspx

Keep going as is till you put up the other antenna...then "retweak" it for your spot...
YEP certainly looks like it's too short.
All the Best
Gary

<blockquote data-quote="BJ radionut" data-source="post: 596633" data-attributes="member: 7026">Frequency in MHz:27.500 MHzLength of full-wave loop:<ul>
<li data-xf-list-type="ul">36 feet, 6.5 inches</li>
<li data-xf-list-type="ul">11.14 meters</li>
</ul>The calculated length is approximate. In practice it&#039;s best to make the antenna a little longer than the calculated value and then trim it to get the best SWR value.Feedpoint impedance and coaxial matching sectionThe feedpoint impedance at the design frequency is about 100 ohms, so full wave loops are often fed with an impedance-matching section made from a piece of 75-ohm coxial cable one quarter wavelength long (shortened to compensate for the velocity factor of the cable).Length of an impedance-matching section with 75-ohm cable with a velocity factor of 0.66 (polyethylene dielectric):<ul>
<li data-xf-list-type="ul">5 feet 10.8 inches</li>
<li data-xf-list-type="ul">1.80 meters</li>
</ul>Length of an impedance matching section made with 75-ohm cable with a cable velocity factor of 0.80 (foam dielectric):<ul>
<li data-xf-list-type="ul">7 feet 1.9 inches</li>
<li data-xf-list-type="ul">2.18 meters</li>
</ul><a href="http://www.66pacific.com/calculators/full-wave-loop-antenna-calculator.aspx" target="_blank">http://www.66pacific.com/calculators/full-wave-loop-antenna-calculator.aspx</a>Keep going as is till you put up the other antenna...then &quot;retweak&quot; it for your spot...YEP certainly looks like it&#039;s too short.All the BestGary</blockquote>

[QUOTE="BJ radionut, post: 596633, member: 7026"] Frequency in MHz: 27.500 MHz [SIZE=4][B]Length of full-wave loop:[/B][/SIZE] [LIST] [*]36 feet, 6.5 inches [*]11.14 meters [/LIST] The calculated length is approximate. In practice it's best to make the antenna a little longer than the calculated value and then trim it to get the best SWR value. [SIZE=4][B]Feedpoint impedance and coaxial matching section[/B][/SIZE] The feedpoint impedance at the design frequency is about 100 ohms, so full wave loops are often fed with an impedance-matching section made from a piece of 75-ohm coxial cable one quarter wavelength long (shortened to compensate for the velocity factor of the cable). Length of an impedance-matching section with 75-ohm cable with a velocity factor of 0.66 (polyethylene dielectric): [LIST] [*]5 feet 10.8 inches [*]1.80 meters [/LIST] Length of an impedance matching section made with 75-ohm cable with a cable velocity factor of 0.80 (foam dielectric): [LIST] [*]7 feet 1.9 inches [*]2.18 meters [/LIST] [URL]http://www.66pacific.com/calculators/full-wave-loop-antenna-calculator.aspx[/URL] Keep going as is till you put up the other antenna...then "retweak" it for your spot... YEP certainly looks like it's too short. All the Best Gary [/QUOTE]

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