[Elecraft] P3 Noise signature

Tue Apr 30 11:20:26 EDT 2013

Our noise generating treadmill is a NordikTrack APEX6100xi model.  I think it is at least 10 to 12 years old.

73, phil, K7PEH

On Apr 30, 2013, at 8:16 AM, Dave Van Wallaghen <w8fgu at comcast.net> wrote:

> Interesting. I have an older treadmill here (15 years+) but have not seen that type of RFI. The bad news is that it needs to be replaced and I'll probably have this issue with a new one.
> 
> Good news is though that I can't work out and operate at the same time. And the tv is usually not on if I'm in the shack unless the wife is home at the same time. Usually not very often though.
> 
> Amazing the sources of RFI these days. I'm still hanging on to most of my 15+ year old appliances just to stay away from newer RFI generators. But like you said, they can radiate over some long distances so I'm sure I'll hear my neighbors stuff like Fred.
> 
> Looks like I might have to pour over Jim, K9YC's RFI doc again ;-)
> 
> 73,
> Dave W8FGU
> 
> 
> 
> On 04/30/2013 11:03 AM, Phil Hystad wrote:
>> RFI...
>> 
>> I have a very pronounced noise on my K3 (and, my Icom Pro III too) on the 80 meter band and it has peaks about 20KHz apart.  Very broad (P3 wave form about 6000 Hz wide and it has slightly bell-shape) and very distinctive in the noise sound you hear on SSB audio.
>> 
>> I know the source though -- it is my wife on the treadmill.  You can almost see and hear the motors and treadmill belt moving by the subtle pulsating of this RFI on the K3 and P3.  It is strong too -- peaks at about 40/9.  And, as an experiment, I got into my truck with my mobile rig (Icom 706) and drove off.  I was a quarter of a mile away by the time the signal strength dropped to a level that I could not hear it anymore.  So, if this is the kind of thing bothering you it does not need to be close.
>> 
>> The good news is that we both prefer going to LA|Fitness rather than work out in our little home gym so this is no longer a big issue but it still happens maybe a few times a month when my wife chooses to work out here.  But, usually that is when I am at work or not on 80 meters which is almost always at night.
>> 
>> 73, phil, K7PEH
>> 
>> 
>> On Apr 30, 2013, at 7:29 AM, Dave Van Wallaghen <w8fgu at comcast.net> wrote:
>> 
>>> Fred,
>>> 
>>> I have a plasma tv here and that sounds close to what I see when it is on. It pretty much wipes out the AM BC band and very ugly for all ham bands 160-10m. I can take a snapshot with my P3 and send it to you if you'd like to compare.
>>> 
>>> Ironically, I just had a daytime RFI issue resolved here. It started a few months ago. I would come home from work in the morning and listen around for awhile and notice the noise would start when the sun came up. Eventually, I noticed it went away at night. It was prominent on 160-20m and it was only detectable on my vertical dipole. I could not hear it on my doublet about 60' away. It was like very rapid lightning type pulse noise. I was starting to think one of my neighbors may have installed a new solar panel array.
>>> 
>>> Long story short, I finally eliminated power sources in the house without relief. I then realized that the vertical dipole was near a garden with some 2-3 year old solar lights my wife put in there. Removing the lights and batteries eliminated the noise. A couple of the fixtures had water in them and my guess is they were the problem. Crazy to think a little solar charger like that could raise so much hell ;-)
>>> 
>>> 73,
>>> Dave W8FGU
>>> 
>>> 
>>> On 04/29/2013 10:17 PM, Fred Jensen wrote:
>>>> I usually check into the No Cal Net on 3533 each night.  I've begun to
>>>> get predictable noise with a unique signature on the P3 WF.  It's a
>>>> series of bands, the first [around 3545] is the widest, they get
>>>> narrower up from that and the separation seems to be about 40 KHz.  The
>>>> higher components get narrower but aren't any weaker.
>>>> 
>>>> Occasionally I've see it come on to an otherwise quiet band, and all the
>>>> "bands" on the WF drift some before stabilizing.
>>>> 
>>>> I have a screen shot from the P3 I'll send, anyone have any idea what
>>>> this is?  I never see it in the daytime on any band, just in the
>>>> evening, which is suspicious ... plasma TV?
>>>> 
>>>> If it's my neighbor Casey, I'll just need to live with it, we don't do
>>>> battle with our neighbors.  Besides, Sampson, their cat, gets along with
>>>> ours and shares his food.
>>>> 
>>>> 73,
>>>> 
>>>> Fred K6DGW
>>>> - Northern California Contest Club
>>>> - CU in the 2013 Cal QSO Party 5-6 Oct 2013
>>>> - www.cqp.org
>>>> 
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>> 
>> 