Topband
[Top] [All Lists]

Re: Topband: New Subject: 160M array feedline question

To: Wes <wes_n7ws@triconet.org>
Subject: Re: Topband: New Subject: 160M array feedline question
From: Mpridesti via Topband <topband@contesting.com>
Reply-to: Mpridesti <mpridesti@yahoo.com>
Date: Mon, 22 Mar 2021 10:18:31 -0400
List-post: <mailto:topband@contesting.com>
If the radials have a good chance be being submerged in fresh water, I would 
consider elevating the radials. 

Had an experience here where my 40 radials on each of my 4 square verticals 
were often times below the water level and radiation efficiency dropped like a 
rock. Great receive performance but transmit signal was poor (think boiling the 
water). When I raised about 20 radials out of the water and disconnected the 
ones now trapped in mud, etc. the 4 square started to play well. 

Regards,

Mark, K1RX


> On Mar 22, 2021, at 9:54 AM, Wes <wes_n7ws@triconet.org> wrote:
> 
> What's the perceived problem with the cable being submerged?
> 
> Wes  N7WS
> 
>> On 3/21/2021 1:25 PM, Carl Braun wrote:
>> Hello Topbanders
>> 
>> I am currently awaiting the snow to melt here in the Northwoods of Wisconsin 
>> before starting the construction of my low band vertical array.  My 
>> verticals will be mounted in a low ground area near a lake and the area 
>> tends to get wet and sometimes floods in the early spring.  Water levels 
>> could reach 6" to 12" above ground.  My concerns relate to the hardline 
>> coaxial cable that will run from my lighting arrestor panel at the outside 
>> of my shack to the center of the two element vertical array which is 250' 
>> away.  I will be using 1 5/8" hardline that I was able to snag for a very 
>> good deal but am concerned about having the cable lying on the ground and 
>> possible become submerged should we get significant rain with the snow melt.
>> 
>> My plan is to elevate the feedline approximately 24" above the ground using 
>> old sections of Rohn 25 tower spaced every 10' or so.  Each vertically 
>> mounted 5' chunk of Rohn 25 will be buried 2' into the ground have a 3' 2x6 
>> board laying horizontally across the tower that would act as a coaxial 
>> "shelf" that will keep the hardline out of the water and prevent any 
>> significant drooping between these Rohn support sections.
>> 
>> My question for the forum is related to the fact that I will have an 
>> elevated coaxial feedline with two ground mounted vertical antennas.  I plan 
>> to use an UNUN or similar line isolator/choke that would keep the hardline 
>> from becoming a extra radial.  Any thoughts from the forum on this set up? 
>> Any extra precautions I should take to keep return currents from flowing on 
>> the feedline?
>> 
>> Thanks in advance for any suggestions.
>> 
>> Carl W9LF
>> 
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
> 
> 
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
<Prev in Thread] Current Thread [Next in Thread>