Hi Wayne:

It's my understanding that the Inverted-L is functionally a vertical with the horizontal wire acting as a top loading capacitor.
Art W6TYP (SK) used this antenna on 160 AM.

-- 
Have Fun,

Brooke Clarke
https://www.PRC68.com
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------

Date: Wed, 26 Feb 2025 06:02:14 +0000 (UTC)
From: "[email protected]" <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Re: [Milsurplus] grc109 into coax fed 1/4 wave 40m vertical
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8

Per the manual, the antenna is supposed to be an end-fed inverted-L of 100ft total length.? 100ft is just 30.48 meters.? About 3/4 wavelength on 40m band.? That should present a fairly high impedance compared to a properly tuned 1/4 vertical with groundplane.? Perhaps the tuneup procedure in the manual is incorrect for that kind of antenna?

Wayne
WB4OGM