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Re: Topband: Antennas and saltwater

To: topband@contesting.com
Subject: Re: Topband: Antennas and saltwater
From: Bjorn SM0MDG <bjorn@sm0mdg.com>
Date: Thu, 29 Dec 2022 15:30:40 +0100
List-post: <mailto:topband@contesting.com>
Stan,

Thanks for the praise! I wish I would have the same RX capabilities as TX, but 
my limited sized rock wont allow for it. Right now I have two pennants, one in 
NW and the other in NE plus a 50 meter BOG in N-S with can be reversed in 
direction but mainly for AF. Fortunately it is rural so the TX antenna is also 
helpful in RX. Normally I listen in diversity with the TX antenna in one ear, 
and one of the RX antennas in the other. I also have a Clifton active whip on 
the site, but its temporarily out of order.

> I tried radials on the ground and in the water but as you and others have 
> said, everything changes with the tide and when the waves get big.  


I have much better consistency in impedance with the "floating ground rods” 
plus a few short radials on ground compared with any of the attempts with 
lifted radials. The trick is to make sure the radials floats within the skin 
effect depth which should be around 12-13” on 160. Rudy suggests a thin sheet 
metal or screen, about 12” deep with a diameter of 12-24" to provide a low- 
resistance ground. I opted for the rods as I had them available and this 
arrangement will still allow me to use the bridge for its intended purpose. 

I will send the photo in email not to bog down the list too much.

73 + HNY de Björn,
SM0MDG
SE0X


> On 29 Dec 2022, at 02:13, Stan Stockton <wa5rtg@gmail.com> wrote:
> 
> 
> Björn,
> 
> I would like to see your picture if you could send it to me.  You are always 
> strong on 160 and now we know why.  
> 
> For the verticals I have put up on a temporary basis very close to the water, 
> I am pleased with just two elevated radials.  I tried radials on the ground 
> and in the water but as you and others have said, everything changes with the 
> tide and when the waves get big.  
> 
> If anyone had a protected area to eliminate the waves and then something that 
> would float with copper sheeting on the bottom, that would be great!  My 
> permanent antenna, a shunt fed tower, is not as close to the water (about 70 
> feet away) and I try to have a reasonably good ground radial system although 
> they are confined to 180 degrees since that tower is very near my property 
> line.  
> 
> A salt water location makes it easy to have a big signal with a relatively 
> simple antenna.  Of course it also causes some corrosion and weatherproofing 
> challenges that stations inland don’t have to worry about so much.  Given a 
> choice, I’ll take the salty water.
> 
> 73… Stan, ZF9CW
> 
>> On Dec 28, 2022, at 8:37 AM, Bjorn SM0MDG <bjorn@sm0mdg.com> wrote:
>> Björn

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