Thanks Jay,
I want to be clear that there are TWO noise types.
1) the S5 to S7 "steady roar" that the pwr line co thought was them but
(apparently) was not.
2) the 14029 vicinity birdies that make about 5 khz of 20m unusable
In summary:
1) Getting a FT100 D with DSP noise reduction has made the 2nd problem
tolerable.
2) If the birdie problem depends on the cooperation of up to 15 neighbors
in this building, I don't believe it's worth chasing.
Now that I'm not chasing problem 1 any longer, I'm going to go back through
the isolation process for problem 2 and see how much the birdies are
reduced by disabling the DSL modem and LinkSys Wireless router that provide
internet for my son and me.
I noticed that the birdies do increase when I get the portable short wave
rcvr in the immediate vicinity of the DSL modem and Wireless router. So
maybe the shielded router suggestion will help reduce this noise.
Will update when I positively confirm wheteher or not our DSL/ROUTER eqpt
are the major source for the birdies.
73,
Frank W0ECS
At 11:39 AM 8/6/2005 -0500, Jay wrote:
>Hi Frank
>
>Wow, you have a tough problem there. When I first moved into the house I
>put a full size 40 meter loop in my attic and heard a lot of various noises
>and spikes and whistles etc. It was annoying but lived with it. Then this
>spring I put up a 135 ft Windom outside and realized how overwhelming the
>extraneous noise that I hear on the attic loop is compared to the Windom
>outside. Given your antenna is in the attic also, I can only imagine what
>those 7 other apartments are doing!! I'm not sure it will be solvable
>because of the proximity to all of the other wiring.
>
>On the repairman not hearing the noise, he may have been using a power line
>sniffer and they typically operate around 300 MHz +/- with a broadband
>detector in order to localize power line interference. I can see why he
>might not have heard the same noise you are hearing.
>
>I just went back and listened again to your noise file. It is clearly some
>kind of electronic device since it is a carrier and not a sporadic noise
>which would be more indicative of an arc induced noise. It does seem pretty
>stable on frequency. The fellow on the SIG that said about a router seems
>to be the best bet and I would also add perhaps some kind of cable or DSL
>modem as a likely source.
>
>Have you tried walking around your apartment building with your handheld
>receiver to see if it peaks up by one of the other apartments?
>Unfortunately it may be on the 2nd floor of one of the other apartments,
>i.e., closer to your antenna, and thus it may be hard to make any kind of an
>assessment. In any case, it appears you are on the right track to maybe get
>a handle on it. Persistence pays!!
>
>Finally, I can also imagine what you neighbors would say if you said you
>wanted to look at their alarm system!! Good Luck.
>
>Jim K5QQ
>
>-----Original Message-----
>From: Frank Brady [mailto:ftbrady@sbcglobal.net]
>Sent: Saturday, August 06, 2005 11:02 AM
>To: Jay Bareman; rfi@contesting.com
>Subject: RE: [RFI] 14028 to 14034 hashbirdietrash
>
>Thanks Jim,
>The pwr line guy had his rcvr connected to my antenna in my shack.
>He was perplexed that he couldn't hear the S5 roar that my TS140 hears.
>I think his expensive receiver is designed to "hear" the stuff they are
>looking for, not the junk our sensitive comm rcvrs hear.
>My antenna is a 20m/30m fan dipole 30 feet above ground in the attic of my
>2nd floor apartment.
>I have gone through all of the ckt brkr routine here in my apartment - the
>noise persists even when brkrs are all off
>
>Our building has 16 units - 8 meters on opposite ends of the building.
>I have also sniffed the 8 meters at our end of the building - no noise with
>my portable short wave (non directional whip ant).
>I have NOT shutdown any of those 8 unit ckt brkrs (not that brave yet).
>I have NOT sniffed the other 8 meters - they are so covered by dense bushes
>its a difficult task.
>Your alarm system (and any other battery backed noise sources) is very
>interesting !
>Our apartments ARE equipped with optional alarm systems (which we opted not
>to pay for).
>
>One final note:
>With all of my apt ckt brkrs OFF, I can sniff a VERY loud buzz on my
>portable short wave rcvr when I put its whip antenna near our bedroom
>ceiling fan. I have explained this to K3RFI Mike Martin rfiservices.com
>and he agreed that this must be because this relatively large mass of metal
>connected to the power wiring is a good antenna to pick up the noise. The
>correct procedure from this point (aside from battery backed noise sources)
>is probably to start shutting down OTHER apartments one by one until the
>noise near my fan goes away. It's just a matter of when I can summon the
>courage to do this.
>
>If the noise is in the alarm systems, I have a feeling that my neighbors
>(who are complete strangers) would be VERY suspicious of someone wanting to
>"sniff" around their security systems - but maybe that's a projection of my
>own paranoia?
>
>73,
>Frank W0ECS
>
>
>
>
>
>
>At 10:17 AM 8/6/2005 -0500, Jim wrote:
>
> >Where did the power line guy have his receiver at when he listened? Did he
> >have it on your antenna or did he have it in his truck out at the curb? If
> >so and if your antenna is in your back yard, maybe this is coming from one
> >of your neighbors houses - assuming you have diligently pulled all of the
> >breakers in your house one at a time. (I don't remember now what you said
> >in your prior postings about your efforts to localize it.)
> >
> >I have noise from my alarm system that sounds somewhat similar and of
>course
> >the problem in finding it is that it is battery backed up so the breaker
> >pulling does not change it.
> >
> >Good Luck
> >
> >Jim K5QQ
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