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You'll need to add at least one 1/4 wave counterpoise in the horizontal plane.

You'll then need to find the tap point on your coil where it's closest to a 50 ohm impedance.
I'd use 12-14ga copperwire and make it 10 turns at your 2.75" diameter, then locate the 50 ohm tap point, the horizontal radial(s?) connect to the bottom of the coil where your coax shield & ground is also connected.

Years ago I recall hearing of a 5/8 10m flagpole antenna with 1/8 wave of straight wire feeding it at the base - which was grounded.

I remember he said he put the shield right to ground with a ground rod at the connection to the 1/8 wave long wire which went straight to the pole just above ground level. It worked great on 10m for both local & dx. I suppose the 4.5' of wire made it appear to be a 50ohm 3/4 wave.

Also, I was wondering if a gamma might actually work if the base of the pole was at ground potential so the apparent impedance would be near zero through the pole right to ground like a dead short (0 ohms) to ground.

I wonder...

<blockquote data-quote="Needle Bender" data-source="post: 396635" data-attributes="member: 13339">You&#039;ll need to add at least one 1/4 wave counterpoise in the horizontal plane.You&#039;ll then need to find the tap point on your coil where it&#039;s closest to a 50 ohm impedance.I&#039;d use 12-14ga copperwire and make it 10 turns at your 2.75&quot; diameter, then locate the 50 ohm tap point, the horizontal radial(s?) connect to the bottom of the coil where your coax shield &amp; ground is also connected.Years ago I recall hearing of a 5/8 10m flagpole antenna with 1/8 wave of straight wire feeding it at the base - which was grounded.I remember he said he put the shield right to ground with a ground rod at the connection to the 1/8 wave long wire which went straight to the pole just above ground level. It worked great on 10m for both local &amp; dx. I suppose the 4.5&#039; of wire made it appear to be a 50ohm 3/4 wave. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f615.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":confused1:" title="Confused&nbsp; &nbsp; :confused1:"&nbsp; data-smilie="5"data-shortname=":confused1:" />Also, I was wondering if a gamma might actually work if the base of the pole was at ground potential so the apparent impedance would be near zero through the pole right to ground like a dead short (0 ohms) to ground.I wonder... <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":)" title="Smile&nbsp; &nbsp; :)"&nbsp; data-smilie="1"data-shortname=":)" /></blockquote>

[QUOTE="Needle Bender, post: 396635, member: 13339"] You'll need to add at least one 1/4 wave counterpoise in the horizontal plane. You'll then need to find the tap point on your coil where it's closest to a 50 ohm impedance. I'd use 12-14ga copperwire and make it 10 turns at your 2.75" diameter, then locate the 50 ohm tap point, the horizontal radial(s?) connect to the bottom of the coil where your coax shield & ground is also connected. Years ago I recall hearing of a 5/8 10m flagpole antenna with 1/8 wave of straight wire feeding it at the base - which was grounded. I remember he said he put the shield right to ground with a ground rod at the connection to the 1/8 wave long wire which went straight to the pole just above ground level. It worked great on 10m for both local & dx. I suppose the 4.5' of wire made it appear to be a 50ohm 3/4 wave. :confused1: Also, I was wondering if a gamma might actually work if the base of the pole was at ground potential so the apparent impedance would be near zero through the pole right to ground like a dead short (0 ohms) to ground. I wonder... :) [/QUOTE]

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