[RFI] Re: repetitive noise
n6kj.kelly at gmail.com
Sun Jan 23 16:55:33 EST 2005
I DF'd it last night with my HF yagi. It doesn't point to my house or
any of my next door neighbors (except maybe my next door neighbor's
garage). I'm going to give my next door neighbor's garage a listen
one of these days. If not there, then it points 1 street over. I
drove the neighborhood last night with my FT-817 (albeit, with an
inefficient whip) and heard nothing. I drove every street in that
direction up to a bout 1 mile away and nothing.
I think the next step is to buy or borrow a W3FF (or similar) portable
dipole. Maybe it will be efficient enough to hear something on my
It doesn't appear to come from my own house.
I don't know how long this has been there. I've noticed it for the
past couple of weeks, but it may have been there longer and I ignored
it. Why? My QRN levels have been surprisingly low for the past 2 or
3 weeks (esp. on 40 meters) so I notice even the smallest bit of noise
On Sun, 23 Jan 2005 12:34:32 -0500, Jim Jarvis <jimjarvis at comcast.net> wrote:
> All manner of sequential-starting things might be the
> source. Misbehaving thermostat...fishtank heater or home
> type... Fluorescent light, with a bad bulb, which doesn't
> ignite properly. Could be a motor starting, but the rep rate
> and pulse duration doesn't sound right.
> Your WAV file sounds like a dirty oscillator, with a clipped,
> triangular kind of waveform. Might be a light dimmer.
> I think timing is the key to finding this, along with elimination
> of sources by disabling the power.
> Start with your own house...run on battery, and kill your primary
> power, to see if it's in your house. Then, work methodically with
> neighbors to do the same.
> If you can get a peak on the beam, that might help give you direction,
> but being able to hear it in a portable radio is critical.
> Odds are, when you find this,you'll be doing someone else
> a favor, by eliminating either noise in their home, or a
> fire hazard.
> I had one of these, in NJ, and eventually tracked it
> down to a loose connection on a circuit breaker in a neighbor's
> main distribution box. The breaker was defective, and caused a hot
> wire in the box, burning the insulation. In that case, though, the
> noise was on or off...it didn't shift in pitch as yours does.
> Good luck!
> jimjarvis at ieee.org
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