RE: [Repeater-Builder] 2 meter noise help!

[Eric Lemmon]

Chris,

If the "large roof fans" are belt-driven, it is possible that the drive
belts are worn enough to create a continuous static generator, similar to a
Van de Graff generator.  If you can, try turning off such fans just long
enough to coast to a stop, and see if the noise changes.  There are
conductive belt dressings available to mitigate such sparking.

If the interfering noise is on-channel, there's not much you can do to
filter it out.  But, you might try setting up a radio that is equipped with
a noise blanker circuit, to see if that helps.

As others have mentioned, power lines can generate a lot of noise and it's
not just insulators that can cause noise.  Any loose clamp or splice can
cause "micro sparks" that are usually not visible to the naked eye, but can
be located with a directional antenna and a portable radio or scanner.  Be
aware that the noise may be generated from many poles, and that makes
precise location very difficult.

73, Eric Lemmon WB6FLY
  

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Christopher K.
Greenhalgh
Sent: Monday, January 26, 2009 12:25 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] 2 meter noise help!

While not a true repeater, I hoping the gurus here can help me.
 
Station info can be seen here; http://www.n8wct.com/n8wct-4/
 
 
The noise is a subtle low-frequency "bacon crackling". It is apparent across
the whole 2 meter band. Every piece of (my) equipment has been replaced, or
substituted. We even bypassed the filter, turned everything off, and the
noise was still present, even on battery power. SWR is fine...the station
can be heard 90 miles away.
 
Even though the noise is subtle, the "pops" seem to be on frequency with the
packet tones, thus, the radio requires an S8 strong receive signal, before
the TNC can decode it!
 
We are pretty sure its environmental...perhaps one of the large roof fans,
a/c unit, or crap from the large adjacent electrical room...whatever it is,
we are guests on the building, and probably would get much sympathy/help
from the owners.
 
Here's where I need help...
 
1. Identifying the source. I have an o-scope, but frankly, don't know much
about how to use it. Is there some sort of antenna analyzer that would help
me with this? Any other comments or advice would be deeply appreciated.
 
2. Repair or eliminate source.
 
Or 3. If I cant repair or eliminate the source, is there a way to filter it
out?
 
This is really a great location, and I'm very eager to remedy the problem,
so if anybody has anything...anything at all, please share.
 
Thanks everyone.
 
73, Chris.
 
_
Chris Greenhalgh, N8WCT
 
www.n8wct.com  
 

 

Re: [Repeater-Builder] 2 meter noise help!

[Jim Miller WB5OXQ in Waco]

Possibly noisy brushes in an elevator generator or motor

  - Original Message - 
  From: Barry 
  To: repeater-builder@yahoogroups.com 
  Sent: Wednesday, January 28, 2009 12:25 PM
  Subject: RE: [Repeater-Builder] 2 meter noise help!


  So have you used a directional setup to determine which direction ?
   , then walk  or drive towards it with an ht or scanner , simple df work , 
sounds like machinery but could be almost anything from a pole insulator to 
your neighbours tv in standby .




--
  To: Repeater-Builder@yahoogroups.com
  From: ch...@n8wct.com
  Date: Mon, 26 Jan 2009 15:24:41 -0500
  Subject: [Repeater-Builder] 2 meter noise help!




  While not a true repeater, I hoping the gurus here can help me.

  Station info can be seen here; http://www.n8wct.com/n8wct-4/

  The noise is a subtle low-frequency "bacon crackling". It is apparent across 
the whole 2 meter band. Every piece of (my) equipment has been replaced, or 
substituted. We even bypassed the filter, turned everything off, and the noise 
was still present, even on battery power. SWR is fine...the station can be 
heard 90 miles away.

  Even though the noise is subtle, the "pops" seem to be on frequency with the 
packet tones, thus, the radio requires an S8 strong receive signal, before the 
TNC can decode it!

  We are pretty sure its environmental...perhaps one of the large roof fans, 
a/c unit, or crap from the large adjacent electrical room...whatever it is, we 
are guests on the building, and probably would get much sympathy/help from the 
owners.

  Here's where I need help...

  1. Identifying the source. I have an o-scope, but frankly, don't know much 
about how to use it. Is there some sort of antenna analyzer that would help me 
with this? Any other comments or advice would be deeply appreciated.

  2. Repair or eliminate source.

  Or 3. If I cant repair or eliminate the source, is there a way to filter it 
out?

  This is really a great location, and I'm very eager to remedy the problem, so 
if anybody has anything...anything at all, please share.

  Thanks everyone.

  73, Chris.

  _
  Chris Greenhalgh, N8WCT

  www.n8wct.com





--
  Let ninemsn property help! Need a new place to rent, share or buy? 

   

Re: [Repeater-Builder] 2 meter noise help!

[Ken Arck]

We used to have a lot of problem with noise on my 2 meter repeater

Fortunately, he finally moved to another state

Ken

Re: [Repeater-Builder] 2 meter noise help!

[kd6aaj]

Yep, sounds like high voltage noise from a dirty insulator, more noticeable in 
foggy conditions. Dirt attracts moisture and at 12,000 Volts (or whatever the 
potential is) you get small shorts that crackle, like in the back of a dirty TV 
set.

If you track it down to a Power Company's insulator, give them a call.

I was working at a saw mill one night when the substation there went down from 
saw dust accumulation on the insulators.

73, KD6AAJ


--- On Wed, 1/28/09, Joe  wrote:

> From: Joe 
> Subject: Re: [Repeater-Builder] 2 meter noise help!
> To: Repeater-Builder@yahoogroups.com
> Date: Wednesday, January 28, 2009, 6:45 AM
> Have you taken a yagi on the roof and tried to determine the
> direction 
> of the noise?  I find that using the AM mode (on my
> handheld scanner or 
> HT) is easier to pinpoint some forms of noise.  You
> didn't say that you 
> eliminated the antenna.  Using the yagi on the roof should
> give you an 
> idea of where (or where not) the noise is coming from.
> 
> I've been off packet radio for years, but one of the
> experiments I 
> always wanted to do is try and audio DSP unit to eliminate
> some forms of 
> noise.  Many people don't realize it, but you have
> discovered how 
> destructive noise can be to a packet AFSK signal.  I had a
> bad power 
> line insulator/tie wire combination outside my house that
> completely 
> decimated my Netrom node digipeater.  The signal sounded
> good to the 
> human ear, but the TNC just couldn't decode anything
> but a full quieting 
> signal.
> 
> 73, Joe, K1ike
> 
> Christopher K. Greenhalgh wrote:
> > While not a true repeater, I hoping the gurus here can
> help me.
> >  
> > Station info can be seen here;
> http://www.n8wct.com/n8wct-4/
> >  
> > The noise is a subtle low-frequency "bacon
> crackling". It is apparent 
> > across the whole 2 meter band. Every piece of (my)
> equipment has been 
> > replaced, or substituted. We even bypassed the filter,
> turned 
> > everything off, and the noise was still present, even
> on battery 
> > power. SWR is fine...the station can be heard 90 miles
> away.
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

  

Re: [Repeater-Builder] 2 meter noise help!

[AJ]

CATV can have leakage from 11 MHz (DCT return carrier) clear up to above
1100 MHz (digital video/data carrier)...

CATV leakage a lot of the time in our experience has been the in home wiring
that is either using poorly shielded cable (i.e. RG59 or Lowes/Home Depot
RG6 or anything from Rat Shack) or has poor cable terminations (crimped on
fittings with pliers, any twist on fittings, gold plated anything
(especially splitters), etc...

While CATV does cause inference if leakage occurs, our larger bandit, at
least in SW Idaho, is commercial power (Idaho Power Co)... It's amazing how
loud of a noise carrier a bad transformer can cause on a site...

73s,

AJ, K6LOR
On Wed, Jan 28, 2009 at 7:04 AM, Mike Wehr  wrote:

>Cable television at your QTH?
>
> Cable can have some leakage... 145mhz area.
>
> 73 de Mike, KO9I
>
>  - Original Message -
> *From:* Christopher K. Greenhalgh 
> *To:* Repeater-Builder@yahoogroups.com
>  *Sent:* Monday, January 26, 2009 2:24 PM
> *Subject:* [Repeater-Builder] 2 meter noise help!
>
>   While not a true repeater, I hoping the gurus here can help me.
>
> Station info can be seen here; http://www.n8wct.com/n8wct-4/
>
> The noise is a subtle low-frequency "bacon crackling". It is apparent
> across the whole 2 meter band. Every piece of (my) equipment has been
> replaced, or substituted. We even bypassed the filter, turned everything
> off, and the noise was still present, even on battery power. SWR is
> fine...the station can be heard 90 miles away.
>
> Even though the noise is subtle, the "pops" seem to be on frequency with
> the packet tones, thus, the radio requires an S8 strong receive signal,
> before the TNC can decode it!
>
> We are pretty sure its environmental...perhaps one of the large roof fans,
> a/c unit, or crap from the large adjacent electrical room...whatever it is,
> we are guests on the building, and probably would get much sympathy/help
> from the owners.
>
> Here's where I need help...
>
> 1. Identifying the source. I have an o-scope, but frankly, don't know much
> about how to use it. Is there some sort of antenna analyzer that would help
> me with this? Any other comments or advice would be deeply appreciated.
>
> 2. Repair or eliminate source.
>
> Or 3. If I cant repair or eliminate the source, is there a way to filter it
> out?
>
> This is really a great location, and I'm very eager to remedy the problem,
> so if anybody has anything...anything at all, please share.
>
> Thanks everyone.
>
> 73, Chris.
>
> _
> Chris Greenhalgh, N8WCT
>
> www.n8wct.com
>
>
>  
>

Re: [Repeater-Builder] 2 meter noise help!

[Mike Wehr]

Cable television at your QTH?

Cable can have some leakage... 145mhz area.

73 de Mike, KO9I
  - Original Message - 
  From: Christopher K. Greenhalgh 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, January 26, 2009 2:24 PM
  Subject: [Repeater-Builder] 2 meter noise help!



  While not a true repeater, I hoping the gurus here can help me.

  Station info can be seen here; http://www.n8wct.com/n8wct-4/

  The noise is a subtle low-frequency "bacon crackling". It is apparent across 
the whole 2 meter band. Every piece of (my) equipment has been replaced, or 
substituted. We even bypassed the filter, turned everything off, and the noise 
was still present, even on battery power. SWR is fine...the station can be 
heard 90 miles away.

  Even though the noise is subtle, the "pops" seem to be on frequency with the 
packet tones, thus, the radio requires an S8 strong receive signal, before the 
TNC can decode it!

  We are pretty sure its environmental...perhaps one of the large roof fans, 
a/c unit, or crap from the large adjacent electrical room...whatever it is, we 
are guests on the building, and probably would get much sympathy/help from the 
owners.

  Here's where I need help...

  1. Identifying the source. I have an o-scope, but frankly, don't know much 
about how to use it. Is there some sort of antenna analyzer that would help me 
with this? Any other comments or advice would be deeply appreciated.

  2. Repair or eliminate source.

  Or 3. If I cant repair or eliminate the source, is there a way to filter it 
out?

  This is really a great location, and I'm very eager to remedy the problem, so 
if anybody has anything...anything at all, please share.

  Thanks everyone.

  73, Chris.

  _
  Chris Greenhalgh, N8WCT

  www.n8wct.com


   

RE: [Repeater-Builder] 2 meter noise help!

[Barry]

So have you used a directional setup to determine which direction ?
 , then walk  or drive towards it with an ht or scanner , simple df work , 
sounds like machinery but could be almost anything from a pole insulator to 
your neighbours tv in standby .

To: Repeater-Builder@yahoogroups.com
From: ch...@n8wct.com
Date: Mon, 26 Jan 2009 15:24:41 -0500
Subject: [Repeater-Builder] 2 meter noise help!























While not a true 
repeater, I hoping the gurus here can help me.
 
Station info can be 
seen here; http://www.n8wct.com/n8wct-4/
 
The noise is a 
subtle low-frequency "bacon crackling". It is apparent across the whole 2 meter 
band. Every piece of (my) equipment has been replaced, or substituted. We even 
bypassed the filter, turned everything off, and the noise was still present, 
even on battery power. SWR is fine...the station can be heard 90 miles 
away.
 
Even though the 
noise is subtle, the "pops" seem to be on frequency with the packet tones, 
thus, 
the radio requires an S8 strong receive signal, before the TNC can decode 
it!
 
We are pretty sure 
its environmental...perhaps one of the large roof fans, a/c unit, or crap from 
the large adjacent electrical room...whatever it is, we are guests on the 
building, and probably would get much sympathy/help from the 
owners.
 
Here's where I need 
help...
 
1. Identifying the 
source. I have an o-scope, but frankly, don't know much about how to use it. Is 
there some sort of antenna analyzer that would help me with this? Any other 
comments or advice would be deeply appreciated.
 
2. Repair or 
eliminate source.
 
Or 3. If I cant 
repair or eliminate the source, is there a way to filter it 
out?
 
This is really a 
great location, and I'm very eager to remedy the problem, so if anybody has 
anything...anything at all, please share.
 
Thanks 
everyone.
 
73, 
Chris.
 
_
Chris Greenhalgh, N8WCT
 
www.n8wct.com
 

  














_
Need a new place to rent, share or buy? Let ninemsn property help
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Re: [Repeater-Builder] 2 meter noise help!

[WD7F - John in Tucson]

Does it sound like popcorn?  We are plagued with SADL/EPLRS from the air 
base here in Tucson, however, it's on UHF.  It's sweeping pulses betweeen 
420 and 450 and since they have an alert commitment, it's on 24/7.  A couple 
years ago, it only occured once in a while but now it's continuous.  I 
haven't heard of anyone having similar on 2 meters.

Just curious.
de WD7F
John in Tucson

- Original Message - 
From: "Joe" 
To: 
Sent: Wednesday, January 28, 2009 7:45 AM
Subject: Re: [Repeater-Builder] 2 meter noise help!


> Have you taken a yagi on the roof and tried to determine the direction
> of the noise?  I find that using the AM mode (on my handheld scanner or
> HT) is easier to pinpoint some forms of noise.  You didn't say that you
> eliminated the antenna.  Using the yagi on the roof should give you an
> idea of where (or where not) the noise is coming from.
>
> I've been off packet radio for years, but one of the experiments I
> always wanted to do is try and audio DSP unit to eliminate some forms of
> noise.  Many people don't realize it, but you have discovered how
> destructive noise can be to a packet AFSK signal.  I had a bad power
> line insulator/tie wire combination outside my house that completely
> decimated my Netrom node digipeater.  The signal sounded good to the
> human ear, but the TNC just couldn't decode anything but a full quieting
> signal.
>
> 73, Joe, K1ike
>
> Christopher K. Greenhalgh wrote:
>> While not a true repeater, I hoping the gurus here can help me.
>>
>> Station info can be seen here; http://www.n8wct.com/n8wct-4/
>>
>> The noise is a subtle low-frequency "bacon crackling". It is apparent
>> across the whole 2 meter band. Every piece of (my) equipment has been
>> replaced, or substituted. We even bypassed the filter, turned
>> everything off, and the noise was still present, even on battery
>> power. SWR is fine...the station can be heard 90 miles away.
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>






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6:15 PM

Re: [Repeater-Builder] 2 meter noise help!

[Joe]

Have you taken a yagi on the roof and tried to determine the direction 
of the noise?  I find that using the AM mode (on my handheld scanner or 
HT) is easier to pinpoint some forms of noise.  You didn't say that you 
eliminated the antenna.  Using the yagi on the roof should give you an 
idea of where (or where not) the noise is coming from.

I've been off packet radio for years, but one of the experiments I 
always wanted to do is try and audio DSP unit to eliminate some forms of 
noise.  Many people don't realize it, but you have discovered how 
destructive noise can be to a packet AFSK signal.  I had a bad power 
line insulator/tie wire combination outside my house that completely 
decimated my Netrom node digipeater.  The signal sounded good to the 
human ear, but the TNC just couldn't decode anything but a full quieting 
signal.

73, Joe, K1ike

Christopher K. Greenhalgh wrote:
> While not a true repeater, I hoping the gurus here can help me.
>  
> Station info can be seen here; http://www.n8wct.com/n8wct-4/
>  
> The noise is a subtle low-frequency "bacon crackling". It is apparent 
> across the whole 2 meter band. Every piece of (my) equipment has been 
> replaced, or substituted. We even bypassed the filter, turned 
> everything off, and the noise was still present, even on battery 
> power. SWR is fine...the station can be heard 90 miles away.