Topband: Antennas and saltwater

[Boye Christensen]

Don't forget to  add a resistor, to avoid stadic building charge:  
10Mohm or so

73 Boye

On 20-12-2022 03:17, GEORGE WALLNER wrote:
> On boat you need to put a capacitor (22 nF or greater) in series with 
> the GND connection. That will stop DC from "melting" your sacrificial 
> anodes.
>
>
> GW
>
>
> On Mon, 19 Dec 2022 17:27:59 -0700 Mark Schoonover  wrote:
>> I did the same thing unfortunately all the sacrificial zincs 
>> disappeared in a few months.
>> On Mon, Dec 19, 2022, 16:18 W7TMT - Patrick <W7TMT at outlook.com> wrote:
>>> I run an 80' high vertical on 160M from my sailboat in the saltwater 
>>> of Puget Sound/Salish Sea near Seattle. After experimenting with a 
>>> number of different saltwater connections I've simplified it to a 
>>> single piece of 1/2" dia. copper pipe 10' long and tapped in the 
>>> middle. I hang it horizontally over the side just below the water 
>>> surface. Works great.
>>>
>>> I recently ran across a post by SE0X running  an 160/80M vertical on 
>>> a floating dock who uses two lengths of suspended pipe. His RBN 
>>> testing suggested that adding a second one made a difference. 
>>> Details here: http://blog.se0x.info/?p=3442#more-3442
>>> 73
>>> Patrick, W7TMT
>>>
>>> -----Original Message-----
>>> From: Topband <topband-bounces+w7tmt=
>>> outlook.com at contesting.com> On Behalf Of GEORGE WALLNER
>>> Sent: Monday, December 19, 2022 14:19
>>> To: Radio KH6O <
>>> radio.kh6o at gmail.com>; topband at contesting.comSubject: Re: Topband: 
>>> Antennas and saltwater
>>>
>>> If the antenna stands in the salt-water or if you have a short, low 
>>> impedance connection to the water, you don't need radials.
>>> During the VK9WWI DXpedition to Willis Islets, we installed a 
>>> vertical on a sand spit that was covered by water most of the time. 
>>> We had 12 radials of various lengths a couple of feet above the 
>>> water. The antenna was fed via an antenna coupler (tuner) mounted on 
>>> its base. Every night during high tide the waves knocked down and 
>>> washed the radials into a tangled mess. For the first three days we 
>>> restored the radials every morning. But we never noticed any 
>>> difference between when the radials were up or when they were in a 
>>> heap at the base of the antenna. After three days we got rid of the 
>>> radials. The antenna had a heavy metal base which was always in 
>>> contact with the water. Ever since then, on various DXpeditions 
>>> (TX3A, VK9GMW, PT0S, etc.), we always put the antennas into the 
>>> water (or the very edge of it where we drive into the sand a 
>>> grounding stake) and never bothered with radials.
>>>
>>> Years ago I had a vertical at C6AGU standing in the water. During 
>>> one night a storm knocked it down. I reinstalled it up the beach 
>>> about 75 feet from the high tide line. I added 16 radials about 3 
>>> feet above the sand, I was told that my 160 m signal was down 10 dB. 
>>> I put the antenna back in the water and had a good signal again. 
>>> Whether the difference was really 10 dB, I don't know. But it was 
>>> substantial. (That was before RBN.) 73, George, AA7JV/C6AGU
>>>
>>> On Mon, 19 Dec 2022 09:23:54 -0800 Radio KH6O  wrote:
>>>>> Ideal is if you can run some RG58 out to the beach and plunk it 
>>>>> next to thewater.  Also use 4 radials there.Enjoy.Ed  N1UR
>>>
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>>
>
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