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Re: [TowerTalk] 160M Antenna puzzlement

To: towertalk@contesting.com
Subject: Re: [TowerTalk] 160M Antenna puzzlement
From: Jeff Blaine <KeepWalking188@ac0c.com>
Date: Mon, 20 Dec 2021 12:11:00 -0600
List-post: <mailto:towertalk@contesting.com>
These guys are right about the radial count, in the absolute sense.  But it's a matter of perspective.

The difference between 8 short radials and 64 long ones is about 3 dB per N6LF.  That's half an S-unit.  It's significant, but in the scheme of things, having a manageable SWR that you can use an amp with (+10 dB on TX) - and a dedicated RX antenna (lower noise floor) will get a guy working more stations in either contesting or DX - than a great ground system alone.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com


On 12/20/21 9:21 AM, Pete Smith N4ZR wrote:
Thanks, Rob, but I'm trying to keep things in some sort of proportion. I'm currently redeploying my K9AY (which was down for the summer - yeah, I know it's overdue) and then I'll see about more radials - I have a comtek plate that has 50 or so connection points, and a lot of WD1A wire.  In the meantime, I'm an alligator, but of course I'm on the East coast.

73, Pete N4ZR
Check out the new Reverse Beacon Network
web server at<http://beta.reversebeacon.net>.
For spots, please use your favorite
"retail" DX cluster.

On 12/20/2021 5:41 AM, Rob Atkinson wrote:
You need way way way more radials, around 60 on ground at a minimum,
and due to copper cost, keeping them at 40 or even 30 feet is better
than a paltry 8 at 65+ feet.  Your feed point resistance will come
down to somewhere between 10 and 15 ohms at the 0 X point.  It's 30 R
because of the minimal radials.

If it were me I'd ditch your feedline arrangement and run directly to
the L from the shack using LDF4-50 if you want the line to last a long
time.  Bring it in to a patch panel or switch in the shack. What I do
is terminate the hardline outside at a drilled out green steel fence
post that has a barrel (a.k.a. bulkhead) dual UHF female connector
mounted on it.  Short run of RG213 comes into the shack from there.
That allows me to disconnect the L outside and pull the 213 away from
the steel post during thunderstorms.   The fence post keeps the
junction up out of the snow in winter, so you may not need it but you
should have an outside disconnect.

Merry Christmas & Happy New Year

Rob
K5UJ
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