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Re: Topband: Noise problem question

To: Steven Raas <sjraas@gmail.com>
Subject: Re: Topband: Noise problem question
From: W2PM <w2pm@aol.com>
Date: Mon, 19 Dec 2011 14:41:18 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
I use a MFJ 1025 with excellent results BUT only on single point noise where 
the sense antenna can be fairly near your main receive antenna.  It's not a 
simple process to get things right and sometimes impossible if the noise is 
coming from different spots or your have multiple sources of it. Nor example, 
several gapping insulators along a power like.  One can be nuller completely.  
Not more tho.  Broadband noise can be a problem too - depends how broad band it 
really is.  You need to get a signature of the noise to try to chacterize it 
and of course you should try to identify at least one source ASAP. Start by 
using VHF am receiver with a small Yagi, them whe I get closer a UHF frequency 
and Yagi.  If its very strong noise it is close by. Could be a neighbors house 
with a crappy switching supply battery charger.  You need more info. 

Sent from my iPad

On Dec 19, 2011, at 14:12, Steven Raas <sjraas@gmail.com> wrote:

> Altho its not a broad signal .. quite the oppisite, I've recently learned
> of the WSPR crowd is running prop beacons @ 1836.6 Just below where the
> majority of the JT65 Activity is, I have rcvd these signals here @ my
> location, along with the Call & Grid they send the TX pwr in dBm Most are
> in the 40 - 30 dBm power level.
> 
> Do you have or know someone that has one of those MFJ noise cancelation
> boxes that uses a 'sense' antenna and you adjust the phase?
> 
> I live in the depths of a big city.. and noise is status quo here.. I
> havent tried one of these devices yet.. if I find a local ham that has
> one.. ide Like to borrow it and see if it would be a viable addition to my
> operations here.
> 
> Good Luck,
> 
> Steve Raas
> N2JDQ
> 
> On Mon, Dec 19, 2011 at 1:55 PM, Joe Giacobello, K2XX <k2xx@swva.net> wrote:
> 
>> Regarding noise on 160M, I have been consistently observing all season
>> long a broad signal, reminiscent of a plasma TV, centered around 1836
>> KHz.  Since it seems to be on 24/7 and my closest neighbor is a half
>> mile away, I don't think it's a TV.  Has anyone else seen this signal or
>> is it just local to me?
>> 
>> 73, Joe
>> K2XX
>> 
>> On 12/19/2011 8:24 AM, Mike(W5UC) wrote:
>>> On 12/18/2011 1:36 PM, W5UN wrote:
>>>> I'm looking for input from someone who has experienced a similar
>>>> situation as I describe below.
>>>> 
>>>> About 3 months ago I began experiencing severe noise on top
>>>> band.  It's a  constant white noise which begins to drop off above
>>>> 2.5 mHz, and is hardly noticeable on 80, and not there at all on 40
>>>> meters and above. Every once and a while the noise will drop off
>>>> completely, only to return a few minutes later. It is there about 98%
>>>> of the time.The severity seems to vary a little, but is typically
>>>> S9+15 db when present, and S3 during the rare times it drops out..
>>>> This noise is coming from the eastern direction, about a mile from
>>>> here. There are power lines.there, and these appear to be the source,
>>>> however there are similar power lines of the same voltage here in
>>>> other directions, including one to the southwest about 800 feet away,
>>>> but that one has no noise. Has anyone experienced such noise as this?
>>>> I need to see if I can track this down and  get it fixed. Any help
>>>> will be appreciated.
>>>> 
>>>> Dave, W5UN
>>> Good Morning Dave:
>>> 
>>> I'm not hearing that here in Lufkin, so it possibly local for you.
>>> 
>>> 73,
>>> Mike, W5UC
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> _______________________________________________
>>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>>> 
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>> 
>>> 
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>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>> 
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
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