Yes, station runs off battery with float charger disconnected from wall.
Have not done a shutdown specific to tracking down this one but have
noted it multiple times while doing a circuit by circuit device by device
noise hunt in my own home.
Pulse noise is there with AC cut, UPSes shutdown and disconnected, etc.
_If_ there was any kind of pattern to the pulses I would have assumed
charger, but it is not the regular, variable rate or multiple burst that I
would normally expect from a battery charger.
It does sound a great deal like the switched PS pulse chargers I have
heard in the past, a little switcher pulsing at 5 - 20 amps like some
electric scooters/etc use. But with those I have always heard multiple
pulses, w/ random repeate, a fixed rate or a variable rate, never more or
less random timing.
On Sat, 11 Jul 2009, Chuck Catledge wrote:
> It *sounds* very much like the noise I hear that comes from a cordless phone
> charger at various areas from 160 up throught at least the FM broadcast
> band. Mine is repetitive though at about a 2 second interval. I presume
> you've switched off circuit breakers while listening. If not, that would be
> my first suggestion.
> Chuck, AE4CW
>> Message: 1
>> Date: Sat, 11 Jul 2009 02:44:11 -0500 (CDT)
>> From: "Christopher E. Brown" <email@example.com>
>> Subject: [RFI] Looking for ideas about yet another noise source
>> To: firstname.lastname@example.org
>> Message-ID: <Pine.LNX.email@example.com>
>> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
>> Attempting to track down a bothersome very intermittant noise and looking
>> for some ideas. Don't have a decent way to record it, but may need to set
>> something up if I cannot make headway.
>> Noise is pulse, appears on at least 80-20, strength higher around 20.
>> On the lower freqs, it is more of a static rush but time compressed, it is
>> also seemingly random, twice in 5 seconds, nothing for 40 sec, once, and
>> so on. Seems to be there almost any time of the day or night.
>> I would think static dischard or random arcing, but on 20m the sound is
>> very un-arc like, thing what would happen if you mixed a high pitched
>> "beep" with someone saying "quip".
>> It would not be so bothersome, but on 20 the pulses are often +40 or so,
>> and screw with the AGC and generally make listening to weak signals on the
>> headphones unpleasant.
>> I would assume this was some sore of pule charger or similar, but it
>> _never_ displays any kind of pattern.
>> I would think intermittant arc except for the sound on 20m.
>> Has me thrown and looking for ideas.
>> RFI mailing list
>> End of RFI Digest, Vol 79, Issue 2
> RFI mailing list
RFI mailing list