Hi Joel, 

In my opinion your elevated radials are a show stopper for an adjacent 
receiving antennas unless you can disconnect all of them when you're 
receiving. 


73 
Frank 
W3LPL 

----- Original Message -----

From: "Joel" <k...@comcast.net> 
To: "Herbert Schoenbohm" <herbert.schoenb...@gmail.com> 
Cc: "TopBand List" <topband@contesting.com>, "kd9sv" <kd...@comcast.net> 
Sent: Wednesday, March 7, 2018 12:48:57 AM 
Subject: Re: Topband: FW: Excessive noise on beverages 

Hi Gary 
Would you send the info you have re. tower detuning that you designed for K3UR. 
(Am using 1/4 wl tower with elevated radials) 
Thank you 
Joel 
k4wm 

Sent from my iPhone 

> On Mar 6, 2018, at 13:42, Herbert Schoenbohm <herbert.schoenb...@gmail.com> 
> wrote: 
> 
> Great work Gary! This is probably a way that is much less expensive than 
> the commercial version of doing this. 
> 
> https://www.lbagroup.com/products/detunipole-detuning-skirt-kit 
> 
> Herb, KV4FZ 
> 
>> On Tue, Mar 6, 2018 at 2:28 PM, kd9sv <kd...@comcast.net> wrote: 
>> 
>> Herb, FYI...gary, kd9sv 
>> 
>> -----Original Message----- 
>> From: kd9sv [mailto:kd...@comcast.net] 
>> Sent: Tuesday, March 06, 2018 12:59 PM 
>> To: 'David Olean' 
>> Subject: RE: Topband: Excessive noise on beverages 
>> 
>> Dave, I have recently developed a simple "tower de-tuning system" that is 
>> in 
>> the "Beta Testing" phase. It will soon be available thru DXE as a system 
>> to 
>> de-tune a tower but I have no plans to use it on towers being used for 
>> transmitting, however; I did design a system for doing that which only 
>> requires adding one RJ1A or Kilovac HC1 type vacuum relay. I built one of 
>> those for K3UL which he has not yet installed. I will send you the drawing 
>> if I can find it on my computer. How are you feeding your tower? Gamma or 
>> what? 
>> 
>> 73, de gary, kd9sv 
>> 
>> -----Original Message----- 
>> From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of David 
>> Olean 
>> Sent: Tuesday, March 06, 2018 12:30 PM 
>> To: Topband Reflector 
>> Subject: Topband: Excessive noise on beverages 
>> 
>> I have been putzing around trying to improve my 160 meter setup, and 
>> have run into a real problem. Most of the USA is covered by two 
>> directions from here in Maine. SW and W. My problem is that I have an 
>> excessively high noise level on both of the beverages that run in these 
>> directions. In the last six months it has gotten worse, and so bad that 
>> I cannot use either beverage. The wires terminate at the side of my 
>> barn where I have ground rods and the RG-6 goes through PVC conduit up 
>> to the shack on the second floor of the barn. During the day I see 
>> noise levels at -133 or -132 on the two wires, but at night the noise 
>> had climbed to levels around -100 or to -110 on a good night. I 
>> suspected that I was getting noise coupled in from my vertical which is 
>> rather close and on the other side of my barn all of 55 ft away. 
>> 
>> Yesterday, I modified the west beverage and shortened it so that it 
>> terminated about 150 feet away from the barn and I ran new coax back 
>> across the field. I kept the SW beverage as is to compare noise levels 
>> at night. Lo and behold, but the noise went to -110 on the SW beverage, 
>> but only about -120 dBm on the modified beverage. This is a 10 dB 
>> improvement. Other directions at night run at about -130, so I am now 
>> seeing a 10 dB extra hit in noise to the west. 
>> 
>> The vertical is a shunt fed Rohn 25 with a total height just over 90 ft 
>> with top loading from a 5 element long boom 10 Meter yagi. I am not sure 
>> if it is possible to simply un resonate this tower. Does anyone have 
>> experience with simple ways to decouple a shunt fed tower from the rx 
>> antennas? 
>> 
>> The extra 10 dB of noise that I get to the west and SW is mostly due to 
>> the location of a town about 7 or 8 miles away in NH. It is ripe with 
>> all sorts of power line noise. I still can't rule out re radiation from 
>> the vertical though! I spent many years fighting with the electric 
>> utility to quell the noise. I involved Riley Hollingsworth and later on, 
>> Laura Smith, his replacement. The effort was futile and I lost heart as 
>> the problem was just too big for one person to fight. I was hoping that 
>> the noise would not affect 160 meters as it had messed up my VHF 
>> exploits, and so far I only have this ten dB swath of noise that bothers 
>> me in two directions. 
>> 
>> Any help with un resonating a shunt fed tower would be appreciated. 
>> 
>> Dave K1WHS 
>> 
>> 
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